ABCMdb

ABCC7 p.Arg74Trp

Admin's notes:	Class II-III (maturation defect, gating defect) Veit et al.
ClinVar:	c.220C>T , p.Arg74Trp D , Likely pathogenic c.221G>A , p.Arg74Gln ? , Uncertain significance
CF databases:	c.220C>T , p.Arg74Trp ? , Varying clinical consequence ; CFTR1: This mutation was found in one CF patient from Southern France. This change does not modify a restriction site; it was detected using the SSCP technique. 140 other chromosomes (normal or CF) have been tested for SSCP's in exon 3; all were negative for R74W. c.221G>A , p.Arg74Gln (CFTR1) ? , This mutation was seen in a patient with chronic pancreatitis (referred by Dr Joan Braganza of the Manchester Pancreato-Biliary Service) whose other chromosome has had no mutation identified mutation. We have seen this mutation only once in over 50 chronic pancreatitis chromosomes screened.
Predicted by SNAP2:	A: D (66%), C: D (71%), D: D (91%), E: D (85%), F: D (91%), G: D (85%), H: D (85%), I: D (85%), K: D (63%), L: D (85%), M: D (85%), N: D (80%), P: D (95%), Q: D (80%), S: D (66%), T: D (75%), V: D (80%), W: D (91%), Y: D (91%),
Predicted by PROVEAN:	A: N, C: N, D: N, E: N, F: N, G: N, H: N, I: N, K: N, L: N, M: N, N: N, P: N, Q: N, S: N, T: N, V: N, W: N, Y: N,

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II-III (maturation defect, gating defect) <a href="https://www.ncbi.nlm.nih.gov/pubmed/26823392">Veit et al.</a>
admin on 2016-08-19 15:16:22

Publications
[hide] Analysis of the complete coding region of the CFTR... Hum Hered. 1999 Mar;49(2):81-4. Loumi O, Baghriche M, Delpech M, Kaplan JC, Bienvenu T
Analysis of the complete coding region of the CFTR gene in ten Algerian cystic fibrosis families.
Hum Hered. 1999 Mar;49(2):81-4., [PMID:10077727]

Abstract [show]
The spectrum of cystic fibrosis (CF) mutations in the North African population remains poorly known. In order to offer an effective diagnostic service and to determine accurate risk estimates, we decided to identify the CF mutations in 10 Algerian CF families. We carried out a chemical-clamp denaturing gradient gel electrophoresis analysis of the CFTR gene and automated direct DNA sequencing. We identified 5 mutations and we characterized 60% of the CF chromosomes. Taking advantage of the homogeneity of the sample, we report clinical features of homozygous CF patients.

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38 Moreover, we have identified a complex mutation R74W-D1270N in the mother of an Algerian 'F508 heterozygous CF patient, and none of these variation were inherited by the child. Login to comment
39 Using intragenic polymorphisms, we have confirmed that R74W and D1270N were not inherited by the 'F508 heterozygous CF child. Login to comment

[hide] Fetal bowel hyperechogenicity may indicate mild at... J Med Genet. 2000 Aug;37(8):E15. Abramowicz MJ, Dessars B, Sevens C, Goossens M, Girodon-Boulandet E
Fetal bowel hyperechogenicity may indicate mild atypical cystic fibrosis: a case associated with a complex CFTR allele.
J Med Genet. 2000 Aug;37(8):E15., [PMID:10922395]

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44 Indeed, mild CFTR mutations or variants combined in cis may produce a more deleterious eVect than each mutation alone, as was recently shown by functional studies in transfected cells for the D1270N-R74W mutations,18 confirming previous observations.19 20 The identification of an increasing number of complex alleles3 21 may partly account for the diYculties in establishing genotype-phenotype correlations. Login to comment

[hide] Adenosine triphosphate-binding cassette superfamil... Biol Reprod. 2001 Aug;65(2):394-400. Larriba S, Bassas L, Egozcue S, Gimenez J, Ramos MD, Briceno O, Estivill X, Casals T
Adenosine triphosphate-binding cassette superfamily transporter gene expression in severe male infertility.
Biol Reprod. 2001 Aug;65(2):394-400., [PMID:11466205]

Abstract [show]
Cystic fibrosis transmembrane regulator (CFTR), multidrug-resistant (MDR)1, and multidrug resistance-associated (MRP) proteins belong to the ATP-binding cassette (ABC) transporter superfamily. A compensatory regulation of MDR1 and CFTR gene expression has been observed in CFTR knockout rodent intestine and in an epithelial cell line of human colon, whereas a high homology and similar anion binding site are shared by MRP and CFTR proteins. To provide better insight into the relationship among the expression behavior in vivo of the three genes in human testis, analysis of MDR1 and MRP gene expression in testicular biopsies was performed and related to the presence of CFTR gene mutations in congenital absence of the vas deferens (CAVD: n = 20) and non-CAVD (n = 30) infertile patients with azoospermia or severe oligozoospermia. A CFTR mutation analysis performed in both groups of patients supported the involvement of CFTR gene mutations in CAVD phenotype (85%) and in defective spermatogenesis (19%). Quantitative reverse transcription-polymerase chain reaction analysis of testicular tissue showed a CFTR-independent MDR1 and MRP gene expression in human testis, suggesting that the mechanisms underlying CFTR gene regulation in testis are different from those in intestine. These findings should contribute to the understanding of patterns of in vivo expression of CFTR, MDR1, and MRP genes in CFTR-related infertility.

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87 Phenotypical and genotypical description of CAVD and non-CAVD infertile patients.a No. patient Phenotype FSH (U/L) Non-CFTR infertility-associated factors Testicular biopsy CFTR mutation M470V polymorphism CAVD infertility 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CBAVD CUAVD CUAVD CUAVD CUAVD 3.1 7.3 3.1 2.4 1.9 3.5 5.7 4.3 3.6 ND 2.2 4.8 11.3 2.1 ND 7.6 5.3 6.5 3.9 21.4 None None None None None None None None None None None None None None None None None None None Yes 1 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes V232D/V232D F508del/R117H F508del/R117H G542X/2789ϩ5GϾA F508del/D1270N ϩ R74W F508del/D1270N ϩ R74W S945L/R258G F508del/5T F508del/5T L206W/5T R117H/N F508del/N Y1014C/N 5T/N N/N N/N Y1092X/R258G 621ϩ1GϾT/5T Q890R/N N/N M/M M/M M/M M/M M/V M/V M/V M/M M/V M/V M/V M/V M/V M/V M/M V/V V/V M/V V/V M/M Non-CAVD infertility 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 TF (SA) TF (SA) TF (SA) TF (SA) TF (SA) TF (SA) TF (SA) TF (SA) TF (SA) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SSO) TF (SA) TF (SA) TF (SSO) OA OA OA OA OA OA OA OA 42.0 15.9 34.8 8.9 26.3 6.4 7.8 15.6 8.7 3.2 3.9 12.6 4.7 1.3 5.6 3.9 6.1 9.3 8.8 19.3 9.6 ND 3.3 5.9 6.6 3.6 1.9 4.2 2.0 4.4 None None None None None None None None None None None None None None None None Yes 2 Yes 2 Yes 2, 3 Yes 4 Yes 5 Yes 6 None None None None None Yes 1 Yes 7 Yes 8 Yes Yes Yes Yes No Yes Yes Yes Yes Yes Yes Yes Yes No No No No No No Yes Yes Yes Yes Yes Yes Yes No Yes Yes Yes F508del/N R334W/N N/N N/N N/N N/N N/N N/N N/N R75Q/N N/N N/N N/N N/N N/N N/N N/N N/N N/N N/N N/N N/N 5T/5T N/N N/N N/N N/N N/N N/N N/N M/M V/V M/V M/V M/V M/V V/V V/V V/V V/V M/V M/V M/V ND V/V M/M M/V M/M M/V M/M M/V V/V M/V M/V M/V V/V V/V M/V M/V V/V a CFTR mutations and M470V allele are also described for each patient. Login to comment

[hide] Spectrum of mutations in the CFTR gene of patients... Genet Test. 2001 Fall;5(3):235-42. Strandvik B, Bjorck E, Fallstrom M, Gronowitz E, Thountzouris J, Lindblad A, Markiewicz D, Wahlstrom J, Tsui LC, Zielenski J
Spectrum of mutations in the CFTR gene of patients with classical and atypical forms of cystic fibrosis from southwestern Sweden: identification of 12 novel mutations.
Genet Test. 2001 Fall;5(3):235-42., [PMID:11788090]

Abstract [show]
Cystic fibrosis (CF) is caused by mutations in the CFTR gene. The spectrum of CFTR mutations varies between populations and depends on different factors, such as ethnic background and geographical location. The extensive CFTR mutation screening of 129 patients with classical or atypical CF from the south-western region of Sweden revealed the presence of 37 CFTR mutations, including 12 novel alleles. The overall mutation detection rate in this study population was 92%, the highest among all tested regions in Sweden. Eight mutations with a frequency above 1% (DeltaF508, 394delTT, R117C, 3659delC, E60X, 1112delT, R764X, and 621 + 1G --> T) accounted for 78% of CF chromosomes and have been recommended for inclusion in the CFTR mutation screening panel for molecular diagnosis of CF in this region. The multiple occurrence of specific CFTR alleles less common than the predominant DeltaF508 mutation (394delTT, R117C, 3659delC) allowed for genotype-phenotype comparisons and revealed consistent relationships between these mutations and disease severity.

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27 MUTATIONS IDENTIFIED IN 258 CHROMOSOMES IN THE CF POPULATION ATTENDING THE SOUTH-WESTERN SWEDISH CF CENTRE Location in the Frequency of Mutation gene, exon Number of mutations mutation (%) Homozygotes Heterozygotes DF508 10 161 62.4 56 49 394delTT 3 13 5.0 3 7 R117C 4 7 2.7 7 3659delC 19 5 1.9 5 E60X 3 4 1.6 4 1112delT 7 4 1.6 1 2 R764X 13 4 1.6 1 2 621 1 1G ® T 4 3 1.2 3 G551D 11 2 0.8 2 I506L 10 2 0.8 2 N1088D (R75Q) 17b 2 0.8 2 Q1238X 19 2 0.8 2 R117H (IVS8-5T) 4 2 0.8 2 V603F (IVS8-5T) 13 2 0.8 2 1716G ® A 10 2 0.8 2 R75Q 3 2 0.8 2 R533X 11 1 0.4 1 2329A ® G Promoter 1 0.4 1 297-3 C ® A 2 1 0.4 1 Y161D 4 1 0.4 1 994del9 Exon/intron 6b 1 0.4 1 1154insTC 7 1 0.4 1 W361R 7 1 0.4 1 T338I 7 1 0.4 1 1249-5A ® G Intron 7 1 0.4 1 1717-2A ® G Intron 10 1 0.4 1 R560T 11 1 0.4 1 E1401X 23 1 0.4 1 3126del4 17a 1 0.4 1 S945L 15 1 0.4 1 R668C 13 1 0.4 1 2622 1 2del6 Intron 13 1 0.4 1 R1162Q Exon 19 1 0.4 1 3849 1 10kbC ® T Intron 19 1 0.4 1 R74W Exon 3 1 0.4 1 2363C ® T Promoter 1 0.4 1 IVS8-5Ta Intron 8 1 0.4 1 Unidentified 20 7.8 Total 258 100 61 116 The new mutations are displayed in bold. Login to comment

[hide] DHPLC screening of cystic fibrosis gene mutations. Hum Mutat. 2002 Apr;19(4):374-83. Ravnik-Glavac M, Atkinson A, Glavac D, Dean M
DHPLC screening of cystic fibrosis gene mutations.
Hum Mutat. 2002 Apr;19(4):374-83., [PMID:11933191]

Abstract [show]
Denaturing high performance liquid chromatography (DHPLC) using ion-pairing reverse phase chromatography (IPRPC) columns is a technique for the screening of gene mutations. In order to evaluate the potential utility of this assay method in a clinical laboratory setting, we subjected the PCR products of 73 CF patients known to bear CFTR mutations to this analytic technique. We used thermal denaturation profile parameters specified by the MELT program tool, made available by Stanford University. Using this strategy, we determined an initial analytic sensitivity of 90.4% for any of 73 known CFTR mutations. Most of the mutations not detected by DHPLC under these conditions are alpha-substitutions. This information may eventually help to improve the MELT algorithm. Increasing column denaturation temperatures for one or two degrees above those recommended by the MELT program allowed 100% detection of CFTR mutations tested. By comparing DHPLC methodology used in this study with the recently reported study based on Wavemaker 3.4.4 software (Transgenomic, Omaha, NE) [Le Marechal et al., 2001) and with previous SSCP analysis of CFTR mutations [Ravnik-Glavac et al., 1994] we emphasized differences and similarities in order to refine the DHPLC system and discuss the relationship to the alternative approaches. We conclude that the DHPLC method, under optimized conditions, is highly accurate, rapid, and efficient in detecting mutations in the CFTR gene and may find high utility in screening individuals for CFTR mutations. Hum Mutat 19:374-383, 2002. Published 2002 Wiley-Liss, Inc.

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42 The following mutations have been studied: exon 3: W57G, R74W, R75Q, G85E, 394delTT, 405+ 1G>A; exon 4: E92X, P99L, 441delA, 444delA, 457TAT>G, D110H, R117C, R117H, A120T, 541delC, 544delCA, Q151X, 621+1G>T, 662- 2A>C; exon 7: 1078delT, F331L, R334W, I336K, R347C, R347P, A349V, R352Q, 1221delCT; exon 10: S492F, Q493X, 1609delCA, deltaI507, deltaF508; exon 11: G542X, S549N, G551D, R553X, A559T, R560K, R560T; exon 13: K716X, Q685X, G628R, L719X; exon 17b: H1054D, G1061R, 3320ins5, R1066H, R1066L, R1070Q, 3359delCT, L1077P, H1085R, Y1092X; exon 19: R1162X, 3659delC, 3662delA, 3667del4, 3737delA, I1234V, S1235R, 3849G>A; exon 20: 3860ins31,S1255X,3898insC,3905insT,D1270N, W1282X, Q1291R; and exon 21: N1303H, N1303K, W1316X. Login to comment
69 profiles of two exon 3 mutations, W57G and R74W, did not resolve from those of the normal sample at the recommended temperature of 55°C (Fig. 2). Login to comment
81 Two mutations (W57G and R74W) were not distinguished from the control sample at the temperature recommended by the MELT program. Login to comment
100 Optimization of Temperature (OTm) for Undetected Mutations Nucleotide RTm OTm Exon Mutation change (°C) (°C) 3 W57G 301 T>G 55 57 R74W 352 C>T 55 57 7 R334W 1132 C>T 58 60 R347C 1171 C>T 58 60 10 Q493X 609 C>T 55 56 20 3905 insT 3905 insT 55 56 D1270N 3940 G>A 57 58 RTm, recommended temperature by the MELT program; OTm, optimized temperature. Login to comment

[hide] The I148T CFTR allele occurs on multiple haplotype... Genet Med. 2002 Sep-Oct;4(5):319-23. Rohlfs EM, Zhou Z, Sugarman EA, Heim RA, Pace RG, Knowles MR, Silverman LM, Allitto BA
The I148T CFTR allele occurs on multiple haplotypes: a complex allele is associated with cystic fibrosis.
Genet Med. 2002 Sep-Oct;4(5):319-23., [PMID:12394343]

Abstract [show]
PURPOSE: To determine whether intragenic changes modulate the cystic fibrosis (CF) phenotype in individuals who are positive for the I148T allele. METHODS: The genes from individuals who carried at least one copy of the I148T allele were analyzed for additional changes that may be acting as genetic modifiers. RESULTS: Seven of eight individuals with a known or suspected diagnosis of CF who carried I148T in combination with a severe CF mutation also carried 3199del6. Eight apparently healthy adult individuals who were compound heterozygous for I148T and a severe CF mutation or homozygous for I148T did not carry the deletion ( = 0.0014). The I148T allele occurs on at least three haplotypes: an IVS-8 9T background, a 7T background, or a 9T + 3199del6 background. The 3199del6 allele was not identified in 386 non-CF chromosomes. CONCLUSIONS: It is concluded that I148T occurs on at least three haplotypes and the complex allele I148T + 9T + 3199del6 is associated with a classic CF phenotype.

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108 For example, the complex allele composed of R74W and D1270N is known to produce variable phenotypes. Login to comment
109 In vitro studies of chloride channel function showed that R74W Table 3 3199del6 and poly(T) analysis in individuals who carry one copy of I148T Intron 8 poly (T) Indication for testing no. Login to comment
111 has little deleterious effect and could be considered a polymorphism.31 D1270N has a more substantial effect on chloride channel function in this model, with the greatest effect observed in the cells containing the complex allele of R74W ϩ D1270N. Login to comment
112 When in combination with a severe allele on the other chromosome, R74W ϩ D1270N is disease-causing; it was identified in a male with CBAVD, rhinitis, and recurrent respiratory infections.32 However,itwasalsodetectedina25-year-oldwomanwhoseonly clinicalsymptomofCFweretwopositivesweatchloridetests.33 In addition, genotyping programs that detect alleles of unknown functionalconsequence,andunknownpopulationfrequency,are at risk for erroneously reporting two changes in trans that are in fact a complex allele. Login to comment

[hide] Highest heterogeneity for cystic fibrosis: 36 muta... Am J Med Genet. 2002 Dec 1;113(3):250-7. Kilinc MO, Ninis VN, Dagli E, Demirkol M, Ozkinay F, Arikan Z, Cogulu O, Huner G, Karakoc F, Tolun A
Highest heterogeneity for cystic fibrosis: 36 mutations account for 75% of all CF chromosomes in Turkish patients.
Am J Med Genet. 2002 Dec 1;113(3):250-7., 2002-12-01 [PMID:12439892]

Abstract [show]
We analyzed the CFTR locus in 83 Turkish cystic fibrosis patients to identify mutations, haplotypes, and the carrier frequency in the population. We detected 36 different mutations in 125 (75%) of the total 166 CF chromosomes. Seven novel mutations were identified: four missense (K68E, Q493P, E608G, and V1147I), two splice-site (406 -3T > C and 3849 +5G > A), and one deletion (CFTRdele17b,18). The data showed that the Turkish population has the highest genetic heterogeneity at the CFTR locus reported so far. The results of this thorough molecular analysis at the CFTR locus of a population not of European descent shows that CF is not uncommon in all such populations. The large number of mutations present, as well as the high heterogeneity in haplotypes associated with the mutations suggests that most of the mutations have persisted for a long time in the population. Consistently, the carrier frequency is assessed to be high, indicating that the disease in the population is ancient.

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80 Haplotypes Associated With the Mutations Identified in 83 Turkish CF Patients* Mutation Total number of alleles Number of alleles Number of patients Haplotypes Homo Hetero DF508 39 (23.5) 6 7 23 M 28 13 1 0 1 6 7 23 M 30 13 1 0 1 6 9 23 M 31 13 1 0 1 6 7 23 M 31 13 11 4 3 6 7 23 M 7 17 2 0 2 6 7 16 M 31 13 3 1 1 6 7 17 M 31 13 17 5 7 6 7 17 M 32 13 3 1 1 1677delTA 12 (7.2) 7 7 16 V 30 13 12 5 2 2183AA > G 7 (4.2) 7 7 16 M 30 13 1 0 1 7 9 16 M 31 13 4 2 0 7 7 16 M 32 13 2 1 0 G542X 6 (3.6) 6 7 23 M 32 13 6 3 0 F1052V 5 (3.0) 6 7 17 M 7 13 4 1 2 7 5 17 M 7 17 1 0 1 W1282X 5 (3.0) 7 7 17 M 7 17 4 1 2 7 7 17 M 7 18 1 0 1 E92K 4 (2.4) 7 7 16 V 46 13 3 1 1 7 7 17 V 46 13 1 0 1 1525 À 1G > A 4 (2.4) 7 7 17 M 7 17 4 2 0 2789 þ 5G > A 4 (2.4) 7 9 17 M 7 17 3 1 1 7 5 17 M 7 17 1 0 1 N1303K 4 (2.4) 7 7 23 M 31 13 2 0 2 6 7 22 M 30 13 1 0 1 6 7 23 M 30 13 1 0 1 A46D 3 (1.8) 6 9 23 M 31 13 1 0 1 6 7 23 M 31 13 2 1 0 2184insA 3 (1.8) 7 5 17 V 30 13 1 0 1 7 7 16 V 30 13 2 0 2 R1070Q 3 (1.8) 7 7 16 M 31 13 1 0 1 7 7 17 M 31 13 2 0 2 Q493Pa 2 (1.2) 6/7 5 16 M 46 13 2 1 0 3849 þ 5G > Aa 2 (1.2) 7 7 16 M 31 13 2 1 0 CFTRdele17b,18a 2 (1.2) 6 9 16 V - - 2 1 0 K68Ea 1 (0.6) 6 9 17 M 7 13 1 0 1 R74W 1 (0.6) 6 7 16 M 32 16 1 0 1 306delTAGA 1 (0.6) 7 7 16 M 7 17 1 0 1 D110H 1 (0.6) 7 9 16 V 30 13 1 0 1 I125T 1 (0.6) 6 7 23 V 7 16 1 0 1 406 À 3T > Ca 1 (0.6) 7 7 16 V 33 17 1 0 1 I148T 1 (0.6) 6/7 7 16/17 M 7 17/23 1 0 1 621 þ 1G > T 1 (0.6) 6 7 21 V 31 13 1 0 1 R347P 1 (0.6) 7 9 17 V 30 13 1 0 1 S466X 1 (0.6) 7 7 23 M 33 13 1 0 1 L571S 1 (0.6) 7 7 16 V 29 13 1 0 1 1717 À 1G > A 1 (0.6) 7 9 17 M 7 16 1 0 1 E608Ga 1 (0.6) 7 9 16 M/V 29/31 13 1 0 1 2043delG 1 (0.6) 7 9 17 M 7 17 1 0 1 P1013L 1 (0.6) 6 5 16 M 21 18 1 0 1 R1066L 1 (0.6) 7 7 17 M 7 13 1 0 1 3129del4 1 (0.6) 7 7 16 V 29 13 1 0 1 V1147Ia 1 (0.6) 6 7 17 M 33 17 1 0 1 S1235R 1 (0.6) 6 7 17 M 39 13 1 0 1 CFTRdele2,3 1 (0.6) 7 7 16 V 33 13 1 0 1 Total 125 (75) 125 32 61 *The order of the polymorphisms is IVS6GATT, Tn, IVS8CA, M470V, IVS17BTA and IVS17BCA. Login to comment

[hide] Chronic pancreatitis and cystic fibrosis. Gut. 2003 May;52 Suppl 2:ii31-41. Witt H
Chronic pancreatitis and cystic fibrosis.
Gut. 2003 May;52 Suppl 2:ii31-41., [PMID:12651880]

Abstract [show]
Recent discoveries of trypsinogen and trypsin inhibitor mutations in patients with chronic pancreatitis (CP) support the hypothesis that an inappropriate activation of pancreatic zymogens to active enzymes within the pancreatic parenchyma starts the inflammatory process. Current data suggest that CP may be inherited dominant, recessive, or complex as a result of mutations in the above mentioned or yet unidentified genes. Evaluation of patients with CP should include genetic testing. Cystic fibrosis (CF) is an autosomal recessive inherited disorder caused by mutations in the CF transmembrane conductance regulator (CFTR) gene and is characterised by pancreatic insufficiency and chronic bronchopulmonary infection. The progression and severity of pulmonary disease differs considerably between people with identical CFTR mutations and does not seem to correlate with the type or class of the CFTR mutation. The identification of further disease modifying genetic factors will increase the pathophysiological understanding and may help to identify new therapeutic targets.

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494 Moreover, two of the CFTR mutations found were previously reported as non-disease causing polymorphisms (R1162L, T1220I), five alterations were described for the first time and have not been demonstrated in a previous study of 640 Spanish CF patients.154 In summary, only 4 of 144 asthmatic patients (2.8%) possessed a verified CF causing mutation (R74W, I148T, T582R, and R1066C). Login to comment

[hide] Cystic fibrosis in Uruguay. Genet Mol Res. 2002 Mar 31;1(1):32-8. Luzardo G, Aznarez I, Crispino B, Mimbacas A, Martinez L, Poggio R, Zielenski J, Tsui LC, Cardoso H
Cystic fibrosis in Uruguay.
Genet Mol Res. 2002 Mar 31;1(1):32-8., [PMID:14963811]

Abstract [show]
We conducted clinical and genetic analyses of 52 cystic fibrosis (CF) patients in Uruguay, which is about half of the known affected individuals in the country. A relatively high proportion had a mild presentation, characterized by pancreatic sufficiency (28%), a strong pulmonary component (97%), and borderline sweat electrolyte measurements (25%). Mutational analysis of CF chromosomes demonstrated a relatively low incidence of the DeltaF508 allele (40%) and a large number of other cystic fibrosis conductance regulator mutations, with an overall detection rate of about 71%. Fifteen different mutations were detected in our patients: DeltaF508, G542X, R1162X, G85E, N1303K, R334W, R75Q, R74W, D1270N, W1282X, DeltaI507, 2789+5G-->A, R1066C, -816C/T, R553X, as well as RNA splicing variant IVS8-5T. This group of Uruguayan CF patients has some characteristics in common with other populations of similar origin (Hispanics), as well as some unique characteristics.

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42 RESULTS Genetic analysis led to the detection of 15 different mutations: ∆F508, G542X, R1162X, G85E, N1303K, R334W, R75Q, R74W, D1270N, W1282X, ∆I507, 2789+5G→A, R1066C, R553X and -816C/T. Login to comment
59 Genotypes N Percent ∆F508/∆F508 ∆F508/R1162X ∆F508/G85E ∆F508/G542X ∆F508/5T ∆F508/R334W ∆F508/1303X ∆F508/R1066C ∆F508/Unknown ∆I507/2789+G-A R74W/D1270N N1303K/G542X N1303K/R553K -816C-T/5T 5T/Unknown G542X/Unknown R75Q/Unknown W1282X/Unknown Unknown/Unknown 8 3 3 3 2 2 1 1 11 1 1 1 1 1 2 2 2 1 6 15.4 5.8 5.8 5.8 3.9 3.9 1.9 1.9 21.2 1.9 1.9 1.9 1.9 1.9 3.9 3.9 3.9 1.9 11.5 All individuals had pulmonary symptoms.All those carrying the ∆F508/∆F508 genotype had pancreatic insufficiency. Login to comment

[hide] Improved detection of cystic fibrosis mutations in... Hum Reprod. 2004 Mar;19(3):540-6. Epub 2004 Jan 29. Danziger KL, Black LD, Keiles SB, Kammesheidt A, Turek PJ
Improved detection of cystic fibrosis mutations in infertility patients with DNA sequence analysis.
Hum Reprod. 2004 Mar;19(3):540-6. Epub 2004 Jan 29., [PMID:14998948]

Abstract [show]
BACKGROUND: Accurate determination of mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is critical for genetic counselling and treatment of obstructive azoospermia. Of concern is that detection rates with routine CFTR mutation panels vary widely depending on patient ancestry; and such panels have limited value for azoospermic patients, who are more likely to carry rare mutations. An alternative approach offers comprehensive, CFTR mutation analysis by a DNA sequence method. We investigated whether this method could improve CFTR detection rates in men with obstructive azoospermia in a prospective study of men with obstructive azoospermia and their partners who were referred for genetic counselling and testing at one of two institutions. METHODS: Sixteen patients with congenital absence of the vas deferens (CAVD, n = 14) or idiopathic obstructive azoospermia (n = 2) were studied. DNA from all patients was analysed for mutations by the DNA sequence method. In addition to this method, six men underwent CFTR analysis by a common 25 or 31 mutation panel coupled with poly T analysis. In 10 subjects, common mutation panel findings were inferred from DNA sequence method results. RESULTS: Overall, 12/16 (75%) azoospermic patients had one or more CFTR mutations and/or 5T alleles, including 12 mutations in 10 patients (two compound heterozygotes) and seven 5T alleles in six patients (one homozygote). The sequence method detected all mutations and three variants of unknown significance. By comparison, the common mutation panels detected only 3/12 mutations (25%) and 0/3 variants. CONCLUSION: The DNA sequence method detects more CFTR mutations than common mutation panels. Given the serious, clinical consequences of transmitting such mutations, this study underscores the importance of accurate, CFTR mutation detection in men with obstructive azoospermia and their partners.

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98 Three additional mutations in three female subjects were identi®ed by two other test methods: two mutations (DF508 and G551D) by the common mutation panel and one mutation (R74W) by CSGE. Login to comment
144 With this Table V. Description of female partners of CAVD patients and genetic results Subject no.a Ancestry Common mutation panel Sequence method CSGE method Interpretation Mutation panel/ CSGE/DNA sequence concordance 1F N.E. Cauc. Het. DF508 * * Mutation N/Ab 2F Asian Negative * Het. R74W Mutation No 3F Asian * Negative * No mutation detected Yes 4F Asian-Indian * Negative * No mutation detected Yes 5F Asian * Negative * No mutation detected Yes 6F N.E. Cauc./S.E.Cauc./ Ashkenazi Het. G551D * * Mutation N/Ab 7F Asian-Indian Negative Negative * No mutation detected Yes 8F Asian * Negative * No mutation detected Yes 9F Asian * Negative * No mutation detected Yes 10F S.E. Cauc./Ashkenazi * Negative * No mutation detected Yes 11F Hispanic * Negative * No mutation detected Yes 12F Asian * Negativec * No mutation detected Yes 13F Hispanic ² ² ² N/A N/A 14F S.E. Cauc./Asian * Het. L997F * Mutation Nod 15F Asian-Indian * Het. I807M * Mutation Nod 16F N.E. Cauc. Login to comment

[hide] Mutations of the CFTR gene in Turkish patients wit... Hum Reprod. 2004 May;19(5):1094-100. Epub 2004 Apr 7. Dayangac D, Erdem H, Yilmaz E, Sahin A, Sohn C, Ozguc M, Dork T
Mutations of the CFTR gene in Turkish patients with congenital bilateral absence of the vas deferens.
Hum Reprod. 2004 May;19(5):1094-100. Epub 2004 Apr 7., [PMID:15070876]

Abstract [show]
BACKGROUND: Mutations of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) can cause congenital bilateral absence of the vas deferens (CBAVD) as a primarily genital form of cystic fibrosis. The spectrum and frequency of CFTR mutations in Turkish males with CBAVD is largely unknown. METHODS: We investigated 51 Turkish males who had been diagnosed with CBAVD at the Hacettepe University, Ankara, for the presence of CFTR gene mutations by direct sequencing of the coding region and exon/intron boundaries. RESULTS: We identified 27 different mutations on 72.5% of the investigated alleles. Two-thirds of the patients harboured CFTR gene mutations on both chromosomes. Two predominant mutations, IVS8-5T and D1152H, accounted for more than one-third of the alleles. Five mutations are described for the first time. With one exception, all identified patients harboured at least one mutation of the missense or splicing type. Presently available mutation panels would have uncovered only 7-12% of CFTR alleles in this population cohort. CONCLUSIONS: Although cystic fibrosis is relatively rare in Turkey, CFTR mutations are responsible for the majority of CBAVD in Turkish males. Because of a specific mutation profile, a population-specific panel should be recommended for targeted populations such as CBAVD in Turkey or elsewhere.

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42 2 (2.0)a This study R74W Exon 3 C®T at 352 Amino acid substitution 1 (1.0) Claustres et al. 1993b 359insT Exon 3 Insertion of T within 360±365 Truncation 1 (1.0) Claustres et al. 1995* A349V Exon 7 C®T at 1178 Amino acid substitution 1 (1.0) Audrezet et al. 1993 R334Q Exon 7 G®A at 1133 Amino acid substitution 1 (1.0) Ferec et al. 1994* T388M Exon 8 C®T at 1295 Amino acid substitution 1 (1.0) Zielenski et al. 1996 IVS8-6T Intron 8 Deletion of T between 1342±12 and 1342±6 Aberrant splicing? Login to comment
57 A few other substitutions, e.g. R74W, 2751-15C®G, L997F, are not classic cystic ®brosis mutations but we cannot exclude the possibility that they may contribute to a CBAVD phenotype, and the L997F substitution was reported to be associated with mild forms of cystic ®brosis such as pancreatitis (Gomez Lira et al., 2000). Login to comment
73 (TG)11 7T/ (TG)10 9T M/V 1 (1.9) (TG)11 7T/ (TG)11 7T V/V 1 (1.9) R74W/? Login to comment

[hide] Atypical sinusitis in adults must lead to looking ... Laryngoscope. 2004 May;114(5):839-43. Coste A, Girodon E, Louis S, Pruliere-Escabasse V, Goossens M, Peynegre R, Escudier E
Atypical sinusitis in adults must lead to looking for cystic fibrosis and primary ciliary dyskinesia.
Laryngoscope. 2004 May;114(5):839-43., [PMID:15126740]

Abstract [show]
HYPOTHESES/OBJECTIVES:: In adults, purulent pansinusitis or nasal polyposis starting early in life or that is permanently infected or associated either with chronic bronchial infection, infertility, or situs inversus are uncommon. In these atypical cases of chronic sinusitis (ACS), a primary dysfunction of the mucociliary clearance can be suspected. Adult patients with ACS were therefore investigated to detect primary ciliary dyskinesia (PCD) or cystic fibrosis (CF). STUDY DESIGN: Open, prospective study. PATIENTS AND METHODS: Forty-two patients with ACS were investigated with ciliary beat frequency and ultrastructure analysis in nasal cells and cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation analysis in blood leukocytes. RESULTS: The diagnosis of PCD was confirmed in seven (17%) patients. At least one CFTR gene mutation was detected in 16 (38%) patients. The diagnosis of CF was suggested in three (7%) compound heterozygous patients. Another 13 (31%) patients were heterozygous for a CFTR gene mutation or a complex allele. Comparison of clinical features of ACS showed that only a family history of chronic sinusitis (P <.01) or chronic bronchitis (P <.02) and the presence of diffuse bronchiectasis (P <.0001) or serous otitis media (P <.0001) were significantly more frequent in PCD patients than in patients carrying CFTR gene mutations or those without PCD or CFTR gene mutations. CONCLUSIONS: ACS should be considered a remarkable entity in which congenital abnormalities of epithelial cells are frequently detected (55% of patients). The higher frequency of mutations in ACS patients compared with the general population suggests that heterozygoty for CFTR gene mutation could be a sinusitis-causing status.

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85 Patients CFTR Gene Mutation(s) Sweat Test (mmol/L) CFTR 1 ⌬F508* 3849 ؉ 10kbC3T* 97 CFTR 2 ⌬F508* 3272-26A3G NA CFTR 3 2143delT S1235R NA CFTR 4 R74W-D1270N - NA CFTR 5 G576A-R668C - NA CFTR 6 IVS8-5T - NA CFTR 7 IVS8-5T - NA CFTR 8 R170C - 32 CFTR 9 ⌬F508* - NA CFTR 10 IVS8-5T - 44 CFTR 11 G1069R - 52 CFTR 12 IVS8-5T - 36 CFTR 13 IVS8-5T - NA CFTR 14 G551D* - NA CFTR 15 G542X* - Ͻ40 CFTR 16 F1074L - NA *Mutations detected with the CF-oligonulcleotide ligation assay kit. Login to comment

[hide] A low prevalence of cystic fibrosis in Uruguayans ... Genet Mol Res. 2004 Jun 30;3(2):258-63. Cardoso H, Crispino B, Mimbacas A, Cardoso ME
A low prevalence of cystic fibrosis in Uruguayans of mainly European descent.
Genet Mol Res. 2004 Jun 30;3(2):258-63., [PMID:15266396]

Abstract [show]
Cystic fibrosis is the most common hereditary disease in populations of European descent, with its prevalence depending on the populations and ethnic groups studied. In contrast to Europe and North America, there is little information about this disease in Latin America. Uruguay currently has a human population of 3,000,000, with a low rate of miscegenation and no remaining isolated Amerindian groups. In the present study, we estimated the prevalence of cystic fibrosis in this country based on the detection of DeltaF508 mutation carriers in 500 unrelated individuals and on the frequency of individuals homozygous for this mutation within the affected population. The latter was calculated from the frequency of the different mutations and genotypes observed in a sample of 52 previously described patients with confirmed cystic fibrosis. A theoretical estimate of the prevalence of cystic fibrosis based on anthropological data suggested a frequency of 25 affected individuals/100,000 inhabitants. However, our data indicated that the true prevalence in the population was considerably lower (6.9 cases/100,000 inhabitants).

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38 *G542X, R1162X, G85E, N1303K, R334W, R75Q, R74W, D1270N, W1282X, ∆I507, 2789+5G->A, R1066C, -816C/T, and R553X. Table 1. Login to comment
56 *G542X, R1162X, G85E, N1303K, R334W, R75Q, R74W, D1270N, W1282X, ∆I507, 2789+5G->A, R1066C, -816C/T, R553X. Table 2. Login to comment

[hide] CFTR mutation distribution among U.S. Hispanic and... Genet Med. 2004 Sep-Oct;6(5):392-9. Sugarman EA, Rohlfs EM, Silverman LM, Allitto BA
CFTR mutation distribution among U.S. Hispanic and African American individuals: evaluation in cystic fibrosis patient and carrier screening populations.
Genet Med. 2004 Sep-Oct;6(5):392-9., [PMID:15371903]

Abstract [show]
PURPOSE: We reviewed CFTR mutation distribution among Hispanic and African American individuals referred for CF carrier screening and compared mutation frequencies to those derived from CF patient samples. METHODS: Results from CFTR mutation analyses received from January 2001 through September 2003, were analyzed for four populations: Hispanic individuals with a CF diagnosis (n = 159) or carrier screening indication (n = 15,333) and African American individuals with a CF diagnosis (n = 108) or carrier screening indication (n = 8,973). All samples were tested for the same 87 mutation panel. RESULTS: In the Hispanic population, 42 mutations were identified: 30 in the patient population (77.5% detection rate) and 33 among carrier screening referrals. Five mutations not included in the ACMG/ACOG carrier screening panel (3876delA, W1089X, R1066C, S549N, 1949del84) accounted for 7.55% detection in patients and 5.58% among carriers. Among African American referrals, 33 different mutations were identified: 21 in the patient population (74.4% detection) and 23 in the carrier screening population. Together, A559T and 711+5G>A were observed at a detection rate of 3.71% in CF patients and 6.38% in carriers. The mutation distribution seen in both the carrier screening populations reflected an increased frequency of mutations with variable expression such as D1152H, R117H, and L206W. CONCLUSIONS: A detailed analysis of CFTR mutation distribution in the Hispanic and African American patient and carrier screening populations demonstrates that a diverse group of mutations is most appropriate for diagnostic and carrier screening in these populations. To best serve the increasingly diverse U.S. population, ethnic-specific mutations should be included in mutation panels.

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43 D1270N/R74W analysis A subset of 192 D1270N-positive samples derived from this sample set as well as samples received for a variety of indications and ethnicities were analyzed for the R74W sequence change using LightCycler (Roche) amplification and melting curve analysis. Login to comment
94 To investigate a potential modifying effect of R74W on the D1270N phenotype, we analyzed 192 D1270N-positive individuals for the presence of R74W.29 Patients were of varying ethnicities (46.4% African American, 29.2% Hispanic, 11.9% Caucasian, 12.5% Other/Mix/Not Provided) and indications (Table 4). Login to comment
95 Two individuals with the indication of carrier testing were homozygous for both D1270N and R74W. Login to comment
97 Six individuals carried the genotype of a severe CF mutation (i.e., ⌬F508), one copy of D1270N and one copy of R74W. Login to comment
99 Among those samples (n ϭ 167) received for carrier testing, 169 D1270N alleles and 159 R74W alleles were detected. Login to comment
100 While we were unable to determine phase, overall 94% of individuals with a D1270N allele also carried an R74W allele. Login to comment
101 In this data set there is no apparent correlation between D1270N, R74W, and phenotype. Login to comment
118 There have been similar reports that R74W may be a potential modifier for the clinical phenotype of D1270N.29 The ⌬F508/ D1270N-R74W genotype has been reported in a girl with CF symptoms,41 in 2 CF patients, 3 CBAVD patients,24 and a 27-year-old man with CBAVD, elevated sweat chlorides, recurrent respiratory infection, and rhinitis.35 Our study of 192 D1270N-positive specimens was not suggestive of a role for R74W as a modifying allele, and a definitive explanation for the variable D1270N frequencies remains unknown. Login to comment
128 We appreciate the assistance of Michelle Blalock, of the University of Virginia, for R74W analysis of D1270N-positive specimens and Stephen Lake for support with statistical calculations. Login to comment

[hide] Rapid detection of CFTR gene rearrangements impact... J Med Genet. 2004 Nov;41(11):e118. Niel F, Martin J, Dastot-Le Moal F, Costes B, Boissier B, Delattre V, Goossens M, Girodon E
Rapid detection of CFTR gene rearrangements impacts on genetic counselling in cystic fibrosis.
J Med Genet. 2004 Nov;41(11):e118., [PMID:15520400]

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136 The subjects were divided into three groups according to the results of a previous screening: (i) 43 CF patients who fulfilled the diagnostic criteria of CF15 and who carried a CF mutation, and seven parents of deceased CF patients, a CF mutation having already been identified in the other parent (50 unidentified CF alleles); (ii) 12 CF patients with no identified CF mutation (24 unidentified CF alleles); and (iii) 16 patients apparently homozygous for a CFTR mutation and who had CF (F508del 2n = 6-, 2104insA22109del10, S945L, 3120+1GRA, N1303K) or a CFTR related disease, that is, isolated CBAVD (D110H, R117H, L997F, R74W-D1270N) or DB (R334W, R668C- G576A-D443Y) (0-16 unidentified CF alleles). Login to comment
253 In other respects, the proven homozygous genotype for mild CFTR mutations found in CBAVD or DB patients of the third group, such as R74W-D1270N33 or L997F,6 34-36 is not considered as deleterious enough to account for their disease. Login to comment

[hide] A large-scale study of the random variability of a... Eur J Hum Genet. 2005 Feb;13(2):184-92. Modiano G, Bombieri C, Ciminelli BM, Belpinati F, Giorgi S, Georges M, Scotet V, Pompei F, Ciccacci C, Guittard C, Audrezet MP, Begnini A, Toepfer M, Macek M, Ferec C, Claustres M, Pignatti PF
A large-scale study of the random variability of a coding sequence: a study on the CFTR gene.
Eur J Hum Genet. 2005 Feb;13(2):184-92., [PMID:15536480]

Abstract [show]
Coding single nucleotide substitutions (cSNSs) have been studied on hundreds of genes using small samples (n(g) approximately 100-150 genes). In the present investigation, a large random European population sample (average n(g) approximately 1500) was studied for a single gene, the CFTR (Cystic Fibrosis Transmembrane conductance Regulator). The nonsynonymous (NS) substitutions exhibited, in accordance with previous reports, a mean probability of being polymorphic (q > 0.005), much lower than that of the synonymous (S) substitutions, but they showed a similar rate of subpolymorphic (q < 0.005) variability. This indicates that, in autosomal genes that may have harmful recessive alleles (nonduplicated genes with important functions), genetic drift overwhelms selection in the subpolymorphic range of variability, making disadvantageous alleles behave as neutral. These results imply that the majority of the subpolymorphic nonsynonymous alleles of these genes are selectively negative or even pathogenic.

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33 In the Tajima`s test,19 the null hypothesis of neutrality is rejected if a statistically significant difference between p Common and rare nonsynonymous and synonymous cSNSs G Modiano et al European Journal of Human Genetics Table 1 List of the 61 cSNSsa encountered in the present survey The random samples of genes (and the technique utilized) cSNS variants found NE Italy (DGGE) Central Italy (DGGE) Southern France (DGGE) Northern France (DHPLC) Spain (SSCA) Czechia (DGGE) Hb Â 104 Exon Exon Length (bp) Ref. no. SNS SASc 1st 100d 2nd 500 1st 100d 2nde 1st 100d 2nd 500 1st 100 2nde 82d 72 Abs. Freq. Total sample size q Â 104 se Â 104 NSf Sf 1g 53 0 0 0 0 0/452 0 924 2 111 1 223C4T R31C 1 1 1/500 1 1 0 0/450 0 5 (11) 1 932 (2 432) 45.23 13.61 90 2 224G4T R31L 0 0 0/500 0 0 0 1/450 0 1 1 932 5.17 5.17 10 3 257C4T S42F 0 0 1/500 0 0 0 0/450 0 1 1 932 5.17 5.17 10 3 109 4 334A4G K68E 1 0 0 0/498 0 0 0 0/452 0 0 1 2 504 3.99 3.99 8 5 352C4T R74W 0 0 0 0/498 0 0 0 1/452 0 0 1 2 504 3.99 3.99 8 6 356G4A R75Q 1 7 1 7/498 2 9 2 9/452 0 2 40 (40) 2 504 (2 544) 157.23 24.66 310 7 386G4A G85E 0 0 1 1/498 0 0 0 0/452 0 0 2 2 504 7.99 5.65 16 4 216 8 482G4A R117H 0 0 0 0/292 0 2 0 1/456 0 0 3 2 302 13.03 7.52 26 9 528T4G I132M 0 0 0 0/292 0 0 0 1/456 0 0 1 2 302 4.34 4.34 8 10 575T4C I148T 1 2 0 1/292 0 0 0 1/456 0 1 6 2 302 26.06 10.63 52 5 90 11 640C4T R170C 0 0 0 0/6 0 0 1/448 0 1 1 436 6.96 6.96 14 12 641G4A R170H 1 1 0 0/6 0 0 2/448 0 4 (4) 1 436 (1 930) 20.73 10.35 41 6a 164 0 0 0/6 0 0 0/432 0 0 992 6b 126 0 0 0/6 0 0 0/454 0 942 7 247 0 0 0/6 0 0 0/796 0 1 284 8 93 13 1281G4A L383 0 0 0 0/6 0 0 1/456 0 0 1 1 516 6.60 6.60 13 9 183 14 1402G4A G424S 0 0 0/6 0 0 1/454 0 1 940 10.64 10.64 21 15 1459G4T D443Y 0 0 0/6 0 0 1/454 0 1 940 10.64 10.64 21 10 192 16 1540A4G M470Vh 42 197 30 37/96 39 199 (i) (i) 27 571(736) 1 484 (1 912) 3849.37 111.28 4 735 17 1598C4A S489X 0 0 0 0/96 0 0 0 1/796 0 1 2 374 4.21 4.21 8 18 1648A4G I506V 1 0 0 0/96 0 0 0 0/796 0 1 2 374 4.21 4.21 8 19 1655T4G F508C 0 1 0 0/96 0 0 0 1/796 0 2 2 038 8.42 5.96 17 20 1716G4A Q528 2 16 1 0/96 0 19 i I 5 43 (58) 1 478 (2 024) 286.56 37.08 557 11 95 21 1756G4T G542X 0 2 0 0/134 0 0 0/796 0 0 2 1 984 10.08 7.12 20 22 1764T4G G544 0 0 0 0/134 0 0 1/796 0 0 1 1 984 5.04 5.04 10 23 1784G4A G551D 0 0 0 0/134 0 0 1/796 0 0 1 1 984 5.04 5.04 10 12 87 24 1816G4A V562I 0 0 0 0 1 0 0/450 0 0 1 (1) 2 004 (2 504) 3.99 3.99 8 25 1816G4C V562L 0 0 0 1 0 0 1/450 0 0 2 (3) 2 004 (2 504) 11.98 6.91 24 26 1859G4C G576A 1 2 0 1 11 0 8/450 0 0 23 (27) 2 004 (2 538) 106.38 20.36 213 13 724j 449 27 1997G4A G622D 0 0 0/80 0/96 1 0 0 0/444 0 1 2 002 5.00 5.00 10 28 2082C4T F650 1 0 0/80 0/20 0 0 0 0/444 0 1 (1) 1 926 (2 412) 4.15 4.15 8 29 2134C4T R668C 1 2 0/80 0/96 1 11 0 12/444 0 27(32) 2 002 (2 558) 125.10 21.98 247 275 30 2377C4T L748 0 0 0/6 0 1 1 388 25.77 25.77 52 14a 129 31 2670G4A W846X 0 0 0/6 0 1 0/452 0/80 0 1 1 010 9.90 9.90 20 32 2694T4G T854 33 23 0/6 33 38 149/452 14/80 11 301 1 010 2980.20 143.92 4 184 33 2695G4A V855I 0 0 0/6 0 0 1/452 0/80 0 1 1 010 9.90 9.90 20 14b 38 0 0 0 0/520 0 0 0 0/446 0 2 448 15 251 34 2816G4C S895T 0 0 0/6 0 0 2/436 0 0 2 996 20.08 14.18 40 35 2831A4C N900T 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 36 2988G4C M952I 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 37 3030G4A T966 (2)k (1)k 0 6/436 0 6 (25)k 618 (1814)k 137.82 27.37 272 38 3032T4C L967S 0 0 0/6 0 0 1/436 0 0 1 996 10.04 10.04 20 16 80 0 0 0/498 0 0 0/450 0 0 1 502 17a 151 39 3123G4C L997F 0 2 2 1/494 0 7 1 4/454 0 0 17 2 502 67.95 16.42 135 40 3157G4A A1009T 0 2 0 0/494 0 0 0 0/454 0 0 2 2 502 7.99 5.65 16 41 3212T4C I1027T 1 0 0 0/494 0 0 0 0/454 0 0 1 2 502 4.00 4.00 8 17b 228 42 3286T4G F1052V 1 1 0 1/194 0 0 0 0/452 0 0 3 (3) 2 200 (2 240) 13.39 7.73 27 43 3337G4A G1069R 0 1 0 0/194 0 0 0 0/452 0 0 1 2 200 4.55 4.55 9 CommonandrarenonsynonymousandsynonymouscSNSs GModianoetal 186 EuropeanJournalofHumanGenetics 44 3345G4T Q1071H 0 0 0 0/194 0 1 0 0/452 0 0 1 2 200 4.55 4.55 9 45 3417A4T T1995 1 3 0 0/194 1 1 0 0/452 0 0 6 (8) 2 200 (2 506) 31.92 11.27 64 46 3419T4G L1096R 0 0 0 0/194 1 0 0 0/452 0 0 1 2 200 4.55 4.55 9 47 3477C4A T1115 0 0 0 0/194 0 0 0 1/452 0 0 1 2 200 4.55 4.55 9 18 101 48 3523A4G I1131V 0 0 1 0/10 0 0 0/448 0 0 1 (2) 1 512 (1 908) 10.48 7.07 21 49 3586G4C D1152H 0 0 0 0/10 0 0 1/448 0 0 1 1 512 6.61 6.61 13 19 249 50 3617G4T R1162L 0 0 1 1/494 0 0/260 0 0/454 0 0 2 2 262 8.84 6.25 18 51 3690A4G Q1186 0 0 0 0/494 0 0/260 0 0/454 1 0 1 2 262 4.42 4.42 9 52 3813A4G L1227 0 1 0 0/494 0 0/260 0 0/454 0 0 1 2 262 4.42 4.42 9 53 3837T4G S1235R 1 1 0 1/494 0 4/260 0 7/454 0 1 15 (15) 2 262 (2 310) 69.94 16.71 140 20 156 54 4002A4G P1290 2 3 0/6 3 5 18/454 3/80 2 36 1 012 357.73 58.22 690 21 90 55 4009G4A V1293I 0 0 0/6 0 0/300 0 1/456 0 0 1 1 316 7.60 7.60 15 56 4029A4G T1299 1 0 0/6 0 1/300 0 1/456 0 0 3 (8) 1 316 (2 330) 34.33 12.12 69 57 4041C4G N1303K 1 0 0/6 0 0/300 0 0/456 0 0 1 1 316 7.60 7.60 15 58 4085T4C V1318A 0 0 0/6 0 0/300 0 1/456 0 0 1 1 316 7.60 7.60 15 22 173 0 0 0/18 0 0 0/450 0 0 1 022 23 106 0 0 0 0/6 0 0 0/448 0 1 436 24l 198+3 59 4404C4T Y1424 1 0 0/6 1 2 5/420 0 2 11 (32) 980 (2 516) 127.19 22.34 251 60m 4521G4A Q1463 (21) (16) (3/32) (14/80) (30) (94/420) 15/76 (17) 15 (227) 76 (1052) 2142.86 131.07 3 367 61 4563T4C D1477 0 0 0/6 0 1 0/420 0 0 1 980 10.20 10.20 20 Totals 6 525 9 584 16 109 The bracketed figures include also the RFLP analysis data (see Materials and methods); the NE Italy, Central Italy, Southern and Northern France are each subdivided into two samples where the 1st is made up of 100 genes. 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[hide] Molecular pathology of the CFTR locus in male infe... Reprod Biomed Online. 2005 Jan;10(1):14-41. Claustres M
Molecular pathology of the CFTR locus in male infertility.
Reprod Biomed Online. 2005 Jan;10(1):14-41., [PMID:15705292]

Abstract [show]
Congenital bilateral absence of the vas deferens (CBAVD) is a form of infertility with an autosomal recessive genetic background in otherwise healthy males. CBAVD is caused by cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations on both alleles in approximately 80% of cases. Striking CFTR genotypic differences are observed in cystic fibrosis (CF) and in CBAVD. The 5T allele is a CBAVD mutation with incomplete penetrance. Recent evidence confirmed that a second polymorphic locus exists and is a major CFTR modifier. The development of minigene models have led to results suggesting that CFTR exon 9 is skipped in humans because of unusual suboptimal 5' splice sites. An extremely rare T3 allele has been reported and it has recently been confirmed that the T3 allele dramatically increases exon 9 skipping and should be considered as a 'CF' mutation. Routine testing for the most prevalent mutations in the CF Caucasian population will miss most CFTR gene alterations, which can be detected only through exhaustive scanning of CFTR sequences. Finally, a higher than expected frequency of CFTR mutations and/or polymorphisms is now found in a growing number of monosymptomatic disorders, which creates a dilemma for setting nosologic boundaries between CF and diseases related to CFTR.

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934 p.R74W and p.DI 270N cystic fibrosis causing mutalions? Login to comment

[hide] Optical detection and discrimination of cystic fib... Anal Bioanal Chem. 2005 Mar;381(6):1122-9. Epub 2005 Mar 3. Murphy D, Redmond G
Optical detection and discrimination of cystic fibrosis-related genetic mutations using oligonucleotide-nanoparticle conjugates.
Anal Bioanal Chem. 2005 Mar;381(6):1122-9. Epub 2005 Mar 3., [PMID:15744517]

Abstract [show]
Novel methods for application of oligonucleotide-gold nanoparticle conjugates to selective colorimetric detection and discrimination of cystic fibrosis (CF) related genetic mutations in model oligonucleotide systems are presented. Three-strand oligonucleotide complexes are employed, wherein two probe oligonucleotide-gold nanoparticle conjugates are linked together by a third target oligonucleotide strand bearing the CF-related mutation(s). By monitoring the temperature dependence of the optical properties of the complexes, either in solution or on silica gel plates, melting behaviors may be accurately and reproducibly compared. Using this approach, fully complementary sequences are successfully distinguished from mismatched sequences, with single base mismatch resolution, for Delta F 508, M470V, R74W and R75Q mutations.

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40 Before using each oligonucleotide, a working stock solution was prepared from the sample received from the supplier Fig. 1 Probe and target oligonucleotide sequences relating to the four cystic fibrosis mutations investigated in this study, namely DF 508, M470D, R74W and R75Q mutations. Login to comment
81 The cystic fibrosis-related mutations that were selected for study are as follows: D F 508-a three base deletion of CTT at position 508 of the CFTR gene; M470V-an A to G SNP at position 1540 of the CFTR gene; R74W and R75Q-C to T and G to A SNPs at positions 352 and 356, respectively, of the CFTR gene. Login to comment
113 To explore the applicability and usefulness of oligonucleotide-nanoparticle conjugates for this purpose, the CF-related SNPs R74W (C to T) and R75Q (G to A) were selected for study. Login to comment
116 Denaturation behavior was then investigated for complexes formed using either of four target strand sequence types-mutation-free, R74W-bearing, R75Q-bearing and a sequence bearing both mutations. Login to comment
121 Concerning the melting behavior of the latter complexes, it is observed that dissociation of the R74W-bearing complex (red line) may be clearly distinguished from that of the R75Q-bearing complex (pink line). Login to comment
126 Denaturation behavior of the hybridized nanoparticle aggregates was investigated for complexes formed using either mutation-free, R74W-bearing, or R75Q-bearing target strands of 50 and 72 base length. Login to comment
138 The second and third rows, each labeled ''DF 508`` and ''No mutation``, show Fig. 3a-c R74W and R75Q mutation detection. Login to comment
139 a Thermal dissociation curves for three-strand complexes comprising two oligonucleotide-nanoparticle conjugates and a target oligonucleotide with the following sequence: (blue) mutation-free, (red) R74W mutation, (pink) R75Q mutation, and (brown) both R74W and R75Q mutations, respectively. Login to comment
141 Also, thermal dissociation curves are shown for three-strand complexes comprising two oligonucleotide-nanoparticle conjugates and a target oligonucleotide with the following sequence: (blue) mutation-free, (red) R74W mutation, (pink) R75Q mutation, respectively, for b 50 base and c 72 base targets the denaturation behavior of nanoparticle aggregates formed using target strands of 27 and 24 base length, the former lacking the CTT deletion mutation and the latter bearing the mutation, respectively. Login to comment
144 This method was also applied to SNP mutation detection using the R74W and R75Q oligonucleotide sequences and aggregate hybridization conditions previously described for solution-based mutation detection experiments. Login to comment
145 Denaturation behavior of hybridized nanoparticle aggregates was monitored for complexes formed using either of four target strand sequence types-mutation-free, R74W-bearing, R75Q-bearing and a sequence bearing both mutations. Login to comment
151 Concerning the melting behavior of the aggregates formed using SNP-bearing target strands, it is observed that dissociation of the R74W-bearing complex (third row, 42 °C) may be clearly distinguished from that of the R75Q-bearing complex (fourth row, 33.5 °C) and that melting of the complex formed using the target sequence bearing both mutations may also be very clearly identified at the lowest melting temperature (fifth row, 28.5 °C). Login to comment
157 Using this approach, fully complementary sequences were successfully distinguished from mismatched sequences, with single base mismatch resolution, for DF 508, M470V, R74W and R75Q mutations. Login to comment

[hide] Frequency and phenotypic consequences of the 3199d... Genet Med. 2005 Mar;7(3):210-1. Ruchon AF, Ryan SR, Fetni R, Rozen R, Scott P
Frequency and phenotypic consequences of the 3199del6 CFTR mutation in French Canadians.
Genet Med. 2005 Mar;7(3):210-1., [PMID:15775760]

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81 Are p.I148T, p.R74W and p.D1270N cystic fibrosis causing mutations? Login to comment

[hide] Gender-sensitive association of CFTR gene mutation... Mol Hum Reprod. 2005 Aug;11(8):607-14. Epub 2005 Aug 26. Morea A, Cameran M, Rebuffi AG, Marzenta D, Marangon O, Picci L, Zacchello F, Scarpa M
Gender-sensitive association of CFTR gene mutations and 5T allele emerging from a large survey on infertility.
Mol Hum Reprod. 2005 Aug;11(8):607-14. Epub 2005 Aug 26., [PMID:16126774]

Abstract [show]
Human infertility in relation to mutations affecting the cystic fibrosis transmembrane regulator (CFTR) gene has been investigated by different authors. The role of additional variants, such as the possible forms of the thymidine allele (5T, 7T and 9T) of the acceptor splice site of intron 8, has in some instances been considered. However, a large-scale analysis of the CFTR gene and number of thymidine residues, alone and in combination, in the two sexes had not yet been addressed. This was the aim of this study. Two groups were compared, a control group of 20,532 subjects being screened for perspective reproduction, and the patient group represented by 1854 idiopathically infertile cases. Analyses involved PCR-based CFTR mutations assessment, reverse dot-blot IVS8-T polymorphism analyses, denaturing gradient gel electrophoresis (DGGE) and DNA sequencing. The expected 5T increase in infertile men was predominantly owing to the 5/9 genotypic class. The intrinsic rate of 5T fluctuated only slightly among groups, but some gender-related differences arose when comparing their association. Infertile men showed a significantly enriched 5T + CFTR mutation co-presence, distributed in the 5/9 and 5/7 classes. In contrast, females, from both the control and the infertile groups, showed a trend towards a pronounced reduction of such association. The statistical significance of the difference between expected and observed double occurrence of 5T + CFTR traits in women suggests, in line with other reports in the literature, a possible survival-hampering effect. Moreover, regardless of the 5T status, CFTR mutations appear not to be involved in female infertility. These results underline the importance of (i) assessing large sample populations and (ii) considering separately the two genders, whose genotypically opposite correlations with these phenomena may otherwise tend to mask each other.

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76 This test involved nine subjects from the infertile group, revealing the occurrence of the following rare mutations: E217G, T1054A, W356X, D443Y and 3667insTC in males and L997F and R297Q in females and 29 subjects from the control, in which we found: A1009T, D110Y, E826K, G1069R, G1130A, G194V, I556V, L320F, M348K, M82V, P1290T, R117C, R352W, R74W, S42F, S660T, S911R, S912L, T1086A, T582S, V920L and Y89C. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... Tohoku J Exp Med. 2005 Dec;207(4):279-85. Uzun S, Gokce S, Wagner K
Cystic fibrosis transmembrane conductance regulator gene mutations in infertile males with congenital bilateral absence of the vas deferens.
Tohoku J Exp Med. 2005 Dec;207(4):279-85., [PMID:16272798]

Abstract [show]
Congenital bilateral absence of the vas deferens (CBAVD) is characterized by azoospermia and male infertility. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are associated with cystic fibrosis (CF), the most common autosomal recessive disorder in Caucasians. Recent publications on CBAVD raised the question whether CFTR gene mutations are responsible for CBAVD occurrence or not. This study was conducted to explore the role of CFTR gene mutations in the occurrence of CBAVD-dependent male infertility. Forty-four chromosomes of 22 CBAVD patients from Austrian ancestry were studied. For detection of the most common mutation DeltaF508, a deletion of phenylalanine at the 508th position of mature CFTR chloride channel protein, the 10th exon of the gene was screened by heteroduplex analysis. In order to identify non-DeltaF508 mutations, we also analyzed the entire coding regions, exon/intron boundaries of 27 exons and the 5'- and 3'-untranslated regions of the gene by denaturing gradient gel electrophoresis (DGGE) after polymerase chain reaction. All exons showing different banding patterns on the DGGE gels were sequenced to define existing DNA sequence variations. Among the analyzed 44 chromosomes of 22 patients, disease producing mutations were found in 31.8% (14/44). The most common mutation was DeltaF508 with a frequency of 43% (6/14), followed by R117H with 29% (4/14). Our results indicate that CFTR gene mutations are common but not the only reason for the occurrence of CBAVD-dependent male infertility. We recommend screening of the CFTR gene in these patients.

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28 Other CF mutations, G542X, G551D, D1152H, M470W, R334W, R74W, M952I, W1282X, N1303K, and G85E, are known to be involved in CBAVD etiology (Wang et al. 2002; Danziger et al. 2004). Login to comment

[hide] Identification of CFTR, PRSS1, and SPINK1 mutation... Pancreas. 2006 Oct;33(3):221-7. Keiles S, Kammesheidt A
Identification of CFTR, PRSS1, and SPINK1 mutations in 381 patients with pancreatitis.
Pancreas. 2006 Oct;33(3):221-7., [PMID:17003641]

Abstract [show]
OBJECTIVES: Chronic pancreatitis is a progressive inflammatory disorder leading to irreversible exocrine and/or endocrine impairment. It is well documented that mutations in the cationic trypsinogen (PRSS1) gene can cause hereditary pancreatitis. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) and the serine protease inhibitor Kazal type 1 (SPINK1) genes are also associated with pancreatitis. METHODS: We analyzed 381 patients with a primary diagnosis of chronic or recurrent pancreatitis using the Ambry Test: Pancreatitis to obtain comprehensive genetic information for the CFTR, SPINK1, and PRSS1 genes. RESULTS: The results identified 32% (122/381) of patients with 166 mutant CFTR alleles, including 12 novel CFTR variants: 4375-20 A>G, F575Y, K598E, L1260P, G194R, F834L, S573C, 2789 + 17 C>T, 621+83 A>G, T164S, 621+25 A>G, and 3500-19 G>A. Of 122 patients with CFTR mutations, 5.5% (21/381) also carried a SPINK1 mutation, and 1.8% (7/381) carried a PRSS1 mutation. In addition, 8.9% (34/381) of all patients had 1 of 11 different SPINK1 mutations. Another 6.3% (24/381) of the patients had 1 of 8 different PRSS1 mutations. Moreover, 1.3% of the patients (5/381) had 1 PRSS1 and 1 SPINK1 mutation. A total 49% (185/381) of the patients carried one or more mutations. CONCLUSIONS: Comprehensive testing of the CFTR, PRSS1, and SPINK1 genes identified genetic variants in nearly half of all subjects considered by their physicians as candidates for genetic testing. Comprehensive test identified numerous novel variants that would not be identified by standard clinical screening panels.

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54 Patients With More Than 1 CFTR Mutation CFTR Mutation 1 CFTR Mutation 2 CFTR Mutation 3 No. of Patients deltaF508 5T 3 deltaF508 D1152H 1 deltaF508 deltaF508 1 deltaF508 F575Y 1 deltaF508 K598E 1 deltaF508 T164S 1 deltaF508 R74W D1270N 1 deltaF508 Q1476X 1 deltaF508 L997F 1 R553X D1152H 1 R553X G1069R 1 2789+5 G9A 2183 AA9G 1 3849+10kb C9T L1260P 1 711+3 A to G I1139V 1 1341+1 G9A G194R 5T 1 621+25 A9G 3500-19 C9T 1 R74W V855I 1 G542X R117H 1 G551D F311L 1 G576A R668C 2 K710X L997F 1 L997F L320V 1 G1069R 5T 1 1818+18 G9A 5T 1 F1074L 5T 1 F834L 5T 1 R74Q R297Q 1 R74Q R297Q 5T 1 R785Q 5T 1 R117H 5T 3 deltaF508 I1027T 1 Total patients 36 MutationsinboldfacewouldnothavebeendetectedbytheAmericanCollegeofObstetrics and Gynecology (ACOG)/American College of Medical Genetics (ACMG) mutation panel. Login to comment
83 Patients With SPINK1 and CFTR Mutations SPINK Mutation 1 SPINK Mutation 2 SPINK1 Mutation 3 CFTR Mutation 1 CFTR Mutation 2 No. of Patients 5¶UTR-147 A9G W1282X 1 5¶UTR-41 G9A 5¶UTR-41 G9A D1445N 1 5¶-41 G9A D1270N R74W 1 5¶UTR-81 C9T deltaF508 5T 1 IVS3+184 T9A S1235R 1 IVS3+184 T9A 5T 1 IVS3+184 T9A deltaF508 5T 1 IVS-72delCT R75X 1 L12F IVS3+90 A9T 296+28 A9G 1 L12F IVS3+90 A9T 4375-20 A9G 1 M1R 5¶UTR-147 A9G 5T 1 N34S IVS3-66-65insTTTT N37S Q1352H 1 N34S IVS3-66-65insTTTT L997F 1 N34S 5T 1 N34S IVS3-66-65insTTTT 5T 3 N34S IVS3-66-65insTTTT IVS1-37T 9C deltaF508 R117H 1 N34S IVS3-66-65insTTTT IVS1-37T9C R117H 5T 1 N34S IVS3-66-65insTTTT 621+83 A9G 1 N34S IVS3-66-65insTTTT IVS1-37T9C deltaF508 S1235R 1 Total patients 21 CFTR mutations in boldface would not have been detected by the ACOG/ACMG mutation panel. Login to comment

[hide] Detection of cystic fibrosis transmembrane conduct... Hum Reprod. 2007 May;22(5):1285-91. Epub 2007 Feb 28. Ratbi I, Legendre M, Niel F, Martin J, Soufir JC, Izard V, Costes B, Costa C, Goossens M, Girodon E
Detection of cystic fibrosis transmembrane conductance regulator (CFTR) gene rearrangements enriches the mutation spectrum in congenital bilateral absence of the vas deferens and impacts on genetic counselling.
Hum Reprod. 2007 May;22(5):1285-91. Epub 2007 Feb 28., [PMID:17329263]

Abstract [show]
BACKGROUND: Mutations in the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene have been widely detected in infertile men with congenital bilateral absence of the vas deferens (CBAVD). Despite extensive analysis of the CFTR gene using varied screening methods, a number of cases remain unsolved and could be attributable to the presence of large gene rearrangements, as recently shown for CF patients. METHODS: We carried out a complete CFTR gene study in a group of 222 CBAVD patients with strict diagnosis criteria and without renal anomaly, and searched for rearrangements using a semi-quantitative assay in a subgroup of 61 patients. RESULTS: The overall mutation detection rate was 87.8%, and 82% of patients carried two mutations. Ten out of the 99 different mutations accounted for 74.6% of identified alleles. Four large rearrangements were found in patients who already carried a mild mutation: two known partial deletions (exons 17a to 18 and 22 to 23), a complete deletion and a new partial duplication (exons 11 to 13). The rearrangements accounted for 7% of the previously unknown alleles and 1% of all identified alleles. CONCLUSIONS: Screening for rearrangements should be part of comprehensive CFTR gene studies in CBAVD patients and may have impacts on genetic counselling for the patients and their families.

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50 CFTR mutations were detected in 387 out of 444 alleles (87.2%), most of them being previously described in patients with CF of varying severity, CBAVD or other CFTR diseases: 45% of identified alleles consisted of severe CF mutations (e.g. F508del, W1282X, 2183AA.G); 13.8% of mild or variable CF mutations (e.g. L206W, 3272-26A.G, R117H, D1152H); 36.7% of mild CFTR defects which are currently not considered CF-causing (e.g. IVS8(T)5, Q1352H, the complex alleles [D443Y;G576A;R668C] and [R74W;D1270N]) and 4.5% of rare missense mutations whose effect is difficult to predict (e.g. A959V, G1069R, V1153E). Login to comment
69 Frequent cystic fibrosis transmembrane conductance regulator (CFTR) defects found in congenital bilateral absence of the vas deferens (CBAVD) patients (above 1% among the identified alleles) Mutation No. of alleles % of the 390 identified alleles F508dela 119 30.5 IVS8(T)5a,b 107 27.4 (TG)12(T)5 82 (TG)13(T)5 16 (TG)11(T)5b 9 R117Ha 25 6.4 R668C 9 2.3 [D443Y;G576A;R668C] 6 [G576A;R668C] 2 R668C 1 L206W 7 1.8 D1152H 6 1.5 W1282Xa 5 1.3 [V562I;(TG)11(T)5] 5 1.3 [R74W;D1270 N] 4 1.0 [R74W;D1270 N] 3 [R74W;V201M;D1270 N] 1 Q1352H(G . Login to comment
95 C)] þ [I556V] 1 Apparent homozygosity 3 0-3 1 [R117H] þ [R117H] 1 1 [D110H] þ [D110H] 1 [R74W;D1270 N] þ [R74W;D1270 N] 1 Total 61 57-75 4 F508del, 2221dupA, as well as variants at the IVS8(TG)m(T)n polymorphic site. Login to comment
152 Moreover, genotypes combining two mild alleles were found, such as [R117H] þ [(TG)13(T)5], [(TG)11(T)5;V562I] þ [L997F] or homozygosity for [R74W;D1270N]. Login to comment

[hide] Best practice guidelines for molecular genetic dia... Eur J Hum Genet. 2009 Jan;17(1):51-65. Epub 2008 Aug 6. Dequeker E, Stuhrmann M, Morris MA, Casals T, Castellani C, Claustres M, Cuppens H, des Georges M, Ferec C, Macek M, Pignatti PF, Scheffer H, Schwartz M, Witt M, Schwarz M, Girodon E
Best practice guidelines for molecular genetic diagnosis of cystic fibrosis and CFTR-related disorders--updated European recommendations.
Eur J Hum Genet. 2009 Jan;17(1):51-65. Epub 2008 Aug 6., [PMID:18685558]

Abstract [show]
The increasing number of laboratories offering molecular genetic analysis of the CFTR gene and the growing use of commercial kits strengthen the need for an update of previous best practice guidelines (published in 2000). The importance of organizing regional or national laboratory networks, to provide both primary and comprehensive CFTR mutation screening, is stressed. Current guidelines focus on strategies for dealing with increasingly complex situations of CFTR testing. Diagnostic flow charts now include testing in CFTR-related disorders and in fetal bowel anomalies. Emphasis is also placed on the need to consider ethnic or geographic origins of patients and individuals, on basic principles of risk calculation and on the importance of providing accurate laboratory reports. Finally, classification of CFTR mutations is reviewed, with regard to their relevance to pathogenicity and to genetic counselling.

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144 A (T)5 variant can either be associated with (TG)11, (TG)12, (TG)13, and rarely (TG)15 repeats.74 When (T)5 is found in diagnostic testing, for example, for CBAVD or atypical presentation, determination of Table 4 Classification of CFTR mutations with regard to their potential for causing disease Mutation group Examples CF-causing F508del Mainly nonsense, frameshift, splicing (invariant dinucleotide): G542X, R553X, W1282X, 2183AA4G, 3659delC, 1717-1G4A, 3120+1G4A Missense that severely affects CFTR synthesis or function: G551D, N1303K, R347P 2789+5G4A, 3849+10kbC4T, 3272-26A4G, L206Wa , D1152Ha , (TG)13(T)5a CFTR-related disorders associated L206Wa , D1152Ha , (TG)13(T)5a [R117H;(T)7], (TG)12(T)5, L997F, V562I, [R668C;G576A;D443Y], [R74W;D1270N] (TG)11(T)5b , S1235Rb No clinical consequences 875+40A4G, M470V (1540A4G), I506V (1648A4G), F508C (1655T4G), 1716G4A, 2694T4G, 4002A4G, 2752-15G4C (TG)11(T)5b , S1235Rb Unproven or uncertain clinical relevance Mainly missense mutations G622D, R170H, V938G, I125T Putative splice mutations: 406-6T4C, 2752-26A4G, 3601-17T4C Only a fraction of mutations and patients have been characterized in detail and, with the exception of frequent mutations, only small numbers of patients have been available for the study of most mutations. Login to comment

[hide] Phenotypic characterisation of patients with inter... Thorax. 2009 Aug;64(8):683-91. Epub 2009 Mar 23. Goubau C, Wilschanski M, Skalicka V, Lebecque P, Southern KW, Sermet I, Munck A, Derichs N, Middleton PG, Hjelte L, Padoan R, Vasar M, De Boeck K
Phenotypic characterisation of patients with intermediate sweat chloride values: towards validation of the European diagnostic algorithm for cystic fibrosis.
Thorax. 2009 Aug;64(8):683-91. Epub 2009 Mar 23., [PMID:19318346]

Abstract [show]
BACKGROUND: In patients with symptoms suggestive of cystic fibrosis (CF) and intermediate sweat chloride values (30-60 mmol/l), extensive CFTR gene mutation analysis and nasal potential difference (NPD) measurement are used as additional diagnostic tests and a positive result in either test provides evidence of CFTR dysfunction. To define the phenotype of such patients and confirm the validity of grouping them, patients with intermediate sweat chloride values in whom either additional CF diagnostic test was abnormal were compared with subjects in whom this was not the case and patients with classic CF. METHODS: The phenotypic features of four groups were compared: 59 patients with CFTR dysfunction, 46 with an intermediate sweat chloride concentration but no evidence of CFTR dysfunction (CF unlikely), 103 patients with CF and pancreatic sufficiency (CF-PS) and 62 with CF and pancreatic insufficiency (CF-PI). RESULTS: The CFTR dysfunction group had more lower respiratory tract infections (p = 0.01), more isolation of CF pathogens (p<0.001) and clubbing (p = 0.001) than the CF unlikely group, but less frequent respiratory tract infections with CF pathogens than the CF-PS group (p = 0.05). Patients in the CF-PS group had a milder phenotype than those with PI. Many features showed stepwise changes through the patient groups. CONCLUSION: Patients with intermediate sweat chloride values and two CFTR mutations or an abnormal NPD measurement have a CF-like phenotype compatible with CFTR dysfunction and, as a group, differ phenotypically from patients with intermediate sweat chloride values in whom further CF diagnostic tests are normal as well as from CF-PS and CF-PI patients.

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60 Table 2 CFTR mutations in the patient subgroups CF-PS CFTR dysfunction CF unlikely Genotype Subjects (n) Genotype Subjects (n) Genotype Subjects (n) F508del*/Not found 12 F508del*/3849+10 kb(C.T){ 11 Not found/Not found 39 Not found/Not found 10 F508del*/R117H{ 7 F508del*/Not found 4 F508del*/3849+10 kb(C.T){ 7 F508del*/Not found 7 IVS8-5T{/Not found 1 F508del*/R347P{ 5 Not found/Not found 5 S1235E/E528E 1 F508del*/R117H{ 4 F508del*/D1152H{ 4 No mutation analysis 1 F508del*/2789+5G.A{ 4 F508del*/IVS8-5T{ 4 Total 46 F508del*/S945L* 3 F508del*/S945L* 2 2789+5G.A{/Not found 3 W1282X*/IVS8-5T{ 2 F508del*/3272-26 A.G{ 2 F508del*/R1070W{ 1 F508del*/A455E{ 2 F508del*/L159S 1 F508del*/711+5G.A 2 F508del*/T1246I 1 F508del*/2789+5G.A 2 F508del*/L165S 1 G542X*/R334W{ 2 W1282X*/D1152H{ 1 F508del*/R334W{ 2 R1162X*/D1152H{ 1 R347P{/Not found 2 R347Hu/D1152H{ 1 F508del*/2116delCTAA 1 R553X*/R117H{ 1 F508del*/IVS8-5T{ 1 3659delC*/R117H{ 1 F508del*/D1152H{ 1 3849+10kb(C.T){/G551R 1 F508del*/711+3A.G 1 R1162X*/3849+10 kb(C.T){ 1 F508del*/L206W{ 1 2789+5G.A{/Not found 1 F508del*/I336K{ 1 G542X*/T854A 1 F508del*/G970D 1 R553X*/Q1463H 1 F508del*/L159S 1 S1235R/R668C 1 F508del*/R751L 1 2789+5G.A{/S977F 1 F508del*/E656X 1 No mutation analysis 1 F508del*/4015delA 1 Total 59 F508del*/Y913S 1 F508del*/L165S 1 F508del*/2143delT 1 G551D*/I336K{ 1 G551D*/3272-26A.G{ 1 G551D*/711+3A.G 1 R553X*/4005+2T.C 1 R553X*/E92K{ 1 G542X*/L206W{ 1 W1282X*/I336K 1 R1162X*/3849+10 kb(C.T){ 1 R1162X*/2789+5G.A{ 1 574delA*/3141del9 1 9890X/I105N 1 R334W{/R1070Q{ 1 3272-26A.G{/4218insT 1 3272-26A.G{/L165S 1 711+3A.G/G1244E 1 R352Q/1812-1G.A 1 F1052V/IVS8-5T{ 1 R74W/D1270N 1 1898-3G.A/1898-3G.A 1 1717-1G.A*/R334W{ 1 3659delC*/Not found 1 394delTT/Not found 1 R1162X*/Not found 1 R553X*/Not found 1 R117H{/Not found 1 G85E*/Not found 1 3849+10k(C.T){/Not found 1 Total 103 *Mutation class I, II or III. Login to comment

[hide] Adenosine receptors, cystic fibrosis, and airway h... Handb Exp Pharmacol. 2009;(193):363-81. Com G, Clancy JP
Adenosine receptors, cystic fibrosis, and airway hydration.
Handb Exp Pharmacol. 2009;(193):363-81., [PMID:19639288]

Abstract [show]
Adenosine (Ado) regulates diverse cellular functions in the lung through its local production, release, metabolism, and subsequent stimulation of G-protein-coupled P1 purinergic receptors. The A(2B) adenosine receptor (A(2B)AR) is the predominant P1 purinergic receptor isoform expressed in surface airway epithelia, and Ado is an important regulator of airway surface liquid (ASL) volume through its activation of the cystic fibrosis transmembrane conductance regulator (CFTR). Through a delicate balance between sodium (Na(+)) absorption and chloride (Cl(-)) secretion, the ASL volume is optimized to promote ciliary activity and mucociliary clearance, effectively removing inhaled particulates. When CFTR is dysfunctional, the Ado/A(2B)AR regulatory system fails to optimize the ASL volume, leading to its depletion and interruption of mucociliary clearance. In cystic fibrosis (CF), loss of CFTR function and resultant mucus stasis leaves the lower airways susceptible to mucus obstruction, chronic bacterial infection, relentless inflammation, and eventually panbronchiectasis. Adenosine triphosphate (ATP) also regulates transepithelial Cl(-) conductance, but through a separate system that relies on stimulation of P2Y(2) purinergic receptors, mobilization of intracellular calcium, and activation of calcium-activated chloride channels (CaCCs). These pathways remain functional in CF, and may serve a protective role in the disease. In this chapter, we will review our current understanding of how Ado and related nucleotides regulate CFTR and Cl(-) conductance in the human airway, including the regulation of additional intracellular and extracellular signaling pathways that provide important links between ion transport and inflammation relevant to the disease.

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125 These results, coupled with the previously subject 1 (20 yo) 51-61 ΔF508/- ΔF508/- ΔF508/ Δ1270N/ ΔF508/ P67L G551D R74W (M470V) ΔF508/- 77-100 97 80, 86 (+) sweat, unavailable 74-68 83% 92% 132% 101% 107% 122% Yes Yes Yes Yes Yes No 7 yr 17 yr 2 yr 2 yr 11 yr 5 mo 2 (22 yo) 3 (30 yo) 4 (14 yo) 5 (19 yo) 6 (17 yr) genotype sweat [CI-] FEV1 PS? Login to comment

[hide] Is CFTR 621+3 A>G a cystic fibrosis causing mutati... J Hum Genet. 2010 Jan;55(1):23-6. Epub 2009 Nov 6. Forzan M, Salviati L, Pertegato V, Casarin A, Bruson A, Trevisson E, Di Gianantonio E, Clementi M
Is CFTR 621+3 A>G a cystic fibrosis causing mutation?
J Hum Genet. 2010 Jan;55(1):23-6. Epub 2009 Nov 6., [PMID:19893581]

Abstract [show]
The 621+3 A>G variant of the CFTR gene was initially detected in four Greek patients with a severe form of cystic fibrosis, and it is reported to impair CFTR mRNA splicing. We present three lines of evidence that argue against the pathogenicity of this variant. First, its allelic frequency in the Italian population was 0.4%. Even considering the lowest value in the confidence interval we would expect 10% of Italian CF patients to be heterozygotes for this variant, whereas it has been reported only in one patient (0.04% of Italian CF patients). Second, expression of the 621+3 A>G variant in HeLa cells using a hybrid minigene showed that 39.5+/-1.1% of transcripts were correctly spliced, indicating that its effects on mRNA splicing are similar to those of the CFTR intron 8 5T variant, associated with congenital bilateral absence of vas deferens (CBAVD), but not with CF. Third, we have identified an asymptomatic individual who harbored the 621+3 A>G variant in trans with the Q552X mutation. Because 621+3 A>G is often included in population-screening programs, this information is critical to provide adequate counseling to patients. Further work should be aimed at investigating whether this variant may have a role in CBAVD or atypical CF.

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101 3 Claustres, M., Altieri, J. P., Guittard, C., Templin, C., Chevalier-Porst, F. & Des Georges, M. Are p.I148T, p.R74W and p.D1270N cystic fibrosis causing mutations? Login to comment

[hide] A 10-year large-scale cystic fibrosis carrier scre... J Cyst Fibros. 2010 Jan;9(1):29-35. Epub 2009 Nov 7. Picci L, Cameran M, Marangon O, Marzenta D, Ferrari S, Frigo AC, Scarpa M
A 10-year large-scale cystic fibrosis carrier screening in the Italian population.
J Cyst Fibros. 2010 Jan;9(1):29-35. Epub 2009 Nov 7., [PMID:19897426]

Abstract [show]
BACKGROUND: Cystic Fibrosis (CF) is one of the most common autosomal recessive genetic disorders, with the majority of patients born to couples unaware of their carrier status. Carrier screenings might help reducing the incidence of CF. METHODS: We used a semi-automated reverse-dot blot assay identifying the 47 most common CFTR gene mutations followed by DGGE/dHPLC analysis. RESULTS: Results of a 10-year (1996-2006) CF carrier screening on 57,999 individuals with no prior family history of CF are reported. Of these, 25,104 were couples and 7791 singles, with 77.9% from the Italian Veneto region. CFTR mutations were found in 1879 carriers (frequency 1/31), with DeltaF508 being the most common (42.6%). Subjects undergoing medically assisted reproduction (MAR) had significantly (p<0.0001) higher CF carrier frequency (1/22 vs 1/32) compared to non-MAR subjects. CONCLUSIONS: If coupled to counselling programmes, CF carrier screening tests might help reducing the CF incidence.

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74 For many of these subjects mutations were identified following DGGE and/or dHPLC analysis, and not through the RDB-based test, as gene alterations are "rare"/uncommon [A238V, R352W, S42F, (V201M, D1270N & R74W) and L206W] or because they have never been identified before [D372E (1251T→G) and L1414S (4373T→C)]. Login to comment
97 CF mutation General adult population MAR population n=1879 n=236 ΔF508 42.6 45.7 2183AA→G 5.9 5.9 R1162X 5.7 8.2 N1303K 5.4 5.9 G542X 4.2 3.7 D1152H 3.9 5.0 R553X 3.7 3.1 R117H 3.3 1.8 711+5G→A 2.8 4.1 Q552X 2.8 0.4 2789+5G→A 2.2 3.1 1717-1G→A 2.6 2.8 E527G 2.4 - G85E 2.4 0.9 R334Q 0.9 0.4 W1282X 0.7 0.9 R334W 0.6 - 1898+3A→G 0.5 0.4 R1158X 0.4 - R1066H 0.4 0.4 T338I 0.4 1.8 3849+10Kb C→T 0.4 1.3 3272-26 A→G - 0.9 3132delTG - 0.9 3659 del C - 0.4 4016 ins T - 0.4 1717-8G→A - 0.4 R347H - 0.4 ΔI507 - 0.4 R1070Q - 0.4 Other (16) 5.4 - Table 2a List of CFTR compound heterozygotes in the adult general population. Mutation Health status Disorder Gender Age (years) Notes and refs ΔF508/A238V Infertile CBAVD M 36 (A) ΔF508/R352W Infertile CBAVD M 45 (A) R553X/R334Q M 38 ΔF508/R347H M 53 [17] S42F/D372E (1251T→G) M 39 (A) (B) ΔF508/D110H Infertile M 38 ΔF508/L1414S (4373T→C) Infertile CBAVD M 44 (A) (B) ΔF508/V201M, D1270N & R74W Infertile CBAVD M 44 (A) [18,19] 2183AA→G/L206W Infertile CBAVD M 40 (A) 711+5G→A/ L206W Infertile CBAVD M 40 (A) Table 2b List of CFTR compound heterozygotes in the population enrolled for medically assisted reproduction. Login to comment
99 Notes to Tables: (A) CFTR mutations A238V, R352W, 4006-19del3, S42F, D372E (1251T→G), L1414S (4373T→C), (V201M, D1270N & R74W) and L206W are not included in the RDB-based screening. Login to comment

[hide] Genetic testing in pancreatitis. Gastroenterology. 2010 Jun;138(7):2202-6, 2206.e1. Epub 2010 Apr 20. Ooi CY, Gonska T, Durie PR, Freedman SD
Genetic testing in pancreatitis.
Gastroenterology. 2010 Jun;138(7):2202-6, 2206.e1. Epub 2010 Apr 20., [PMID:20416310]

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53 Interpretation of Mutations Requires an Understanding of Their Functional Consequences Mutation group Reported mutations Complex allele: These mutations are recognized to occur on a single allele R117H ϩ T G576A ϩ R668C F508del ϩ I1027T Benign sequence alterations: These mutations have no known clinical consequence R74Q R297Q R74W 621 * 25 AϾG 3500-19 CϾT T164S C855I I1139V CFTR-related disorder associated: These mutations have been described in individuals with CF-like single organ disease (such as pancreatitis, sinopulmonary disease, or obstructive azoospermia), but do not fulfill the diagnostic criteria for CF 5T R117H D1270N L320V Q1352H 1818-18 GϾA S1235R CF causing F508del Q1476X R553X K710X G542X G551D F311L 2789-5 GϾA 2183AAϾG 711ϩ3 AϾG 3849ϩ10kb CϾT 1341ϩ1GϾA D1152Ha F1074La R553X Unknown clinical consequence F575Y L1260P G194R G1069R L997F K598E F834L R785Q To illustrate this point, mutations identified by extensive mutation testing in a cohort of patients with recurrent acute or chronic pancre- atitis14 are listed according to their clinical consequences (based on current consensus guidelines13 and functional and/or clinical reports; available: http://www.genet.sickkids.on.ca). Login to comment

[hide] Notable contribution of large CFTR gene rearrangem... Eur J Hum Genet. 2010 Oct;18(10):1166-9. Epub 2010 May 26. de Becdelievre A, Costa C, LeFloch A, Legendre M, Jouannic JM, Vigneron J, Bresson JL, Gobin S, Martin J, Goossens M, Girodon E
Notable contribution of large CFTR gene rearrangements to the diagnosis of cystic fibrosis in fetuses with bowel anomalies.
Eur J Hum Genet. 2010 Oct;18(10):1166-9. Epub 2010 May 26., [PMID:20512161]

Abstract [show]
Grade III fetal bowel hyperechogenicity and/or loop dilatation observed at the second trimester of pregnancy can be due to several disease conditions, including cystic fibrosis (CF). Screening for frequent CF mutations is performed as a first step and, in certain situations, such as when a frequent CF mutation is found in the fetus, the increased risk of CF justifies an in-depth study of the second allele. To determine the contribution of large CFTR gene rearrangements in such cases, detected using a semiquantitative fluorescent multiplex PCR (QFM-PCR) assay, we collated data on 669 referrals related to suspicion of CF in fetuses from 1998 to 2009. Deletions were found in 5/70 cases in which QFM-PCR was applied, dele19, dele22_23, dele2_6b, dele14b_15 and dele6a_6b, of which the last three remain undescribed. In 3/5 cases, hyperechogenicity was associated with dilatation and/or gallbladder anomalies. Of the total cases of CF recognized in the subgroup of first-hand referrals, deletions represent 16.7% of CF alleles. Our study thus strengthens the need to consider large CFTR gene rearrangements in the diagnosis strategy of fetal bowel anomalies, in particular in the presence of multiple anomalies.

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48 Table 1 Reasons of screening for large rearrangements In group 1 (first-hand referrals): 17/450 First step of the study: one CF mutation identified (n¼8) F508del (n¼6), 394delTT (n¼1), Q1352H (n¼1) Abnormal AF-DE (n¼4) Consanguinity in the couple (n¼1) Very suggestive ultrasound signsa (n¼4) In group 2 (second-hand referrals): 53/219 First step of the study: one CF mutation identified in another laboratory (n¼45) F508del (n¼36), N1303K (n¼3), G542X (n¼2), G551D, R553X, W1282X, 3849+10kbC4T (n¼1 for each) Abnormal AF-DE (n¼1) Consanguinity in the couple and presence of the [R74W;V201M;D1270N] complex allele (n¼1) Very suggestive ultrasound signsa (n¼6) aVery suggestive ultrasound signs mean that several abnormal signs were associated and/or clinicians insisted on a comprehensive study of the CFTR gene. Login to comment

[hide] Cystic fibrosis newborn screening: using experienc... J Inherit Metab Dis. 2010 Oct;33(Suppl 2):S255-61. Epub 2010 Jun 3. Hale JE, Parad RB, Dorkin HL, Gerstle R, Lapey A, O'Sullivan BP, Spencer T, Yee W, Comeau AM
Cystic fibrosis newborn screening: using experience to optimize the screening algorithm.
J Inherit Metab Dis. 2010 Oct;33(Suppl 2):S255-61. Epub 2010 Jun 3., [PMID:20521170]

Abstract [show]
Newborn screening (NBS) for cystic fibrosis (CF) offers the opportunity for early diagnosis and improved outcomes in patients with CF and has been universally available in the state of Massachusetts since 1999 using an immunoreactive trypsinogen (IRT)-DNA algorithm. Ideally, CF NBS is incorporated as part of an integrated NBS system that allows for comprehensive and coordinated education, laboratory screening, clinical follow-up, and evaluation so that evidence-based data can be used to maximize quality improvements and optimize the screening algorithm. The New England Newborn Screening Program (NENSP) retrospectively analyzed Massachusetts's CF newborn screening data that yielded decisions to eliminate a screen-positive category, maintain the IRT cutoff value that prompts the second tier DNA testing, and communicate CF relative risk to primary care providers (PCPs) based on categorization of positive CF NBS results.

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47 Extensive follow-up Table 1 Children who are followed at a cystic fibrosis (CF) center who were not identified by CF newborn screening (NBS) Presentation Status at last update NBS IRT%, age at dx Genotype Sweat [Cl- ] (MEq/L)a Five CF infants with false-negative CF NBS results FTT, upper respiratory infections, chronic cough Pancreatic sufficient, sinus disease, positive cultures for Staph. aureus and H. flu 84.2%, 3 months DF508/R117H 67 Meconium ileus 93.9%, birth G542X / unknown 57.7, 67.4 FTT, recurrent pneumonia, asthma 62.3%, 4 years D828G / 3271+18 C or T 62 Asthma 78.6%, 3 years D1270N / R74W 86.5 Chronic cough and sinusitis 74.1%, 4 years R75Q / unknown (second mutation not identified by sequencing) 82, 68 Four additional infants followed at CF center who do not (yet) carry a CF diagnosis Chronic cough Pancreatic sufficient, asthma, moderate Staph. aureus and H. flu 39.7%, 5 years DF508 / unknown 39 Chronic cough; sweat-tested and genotyped after parents found to be carriers during pregnancy with younger sibling Does not carry CF diagnosis, pancreatic sufficient, exercise-induced asthma, normal PFTs, cultures Staph. aureus 94.6%, 3 years DF508/R117H 56 Two siblings who are well; genotyped for family history Positive cultures for Staph. aureus and H.flu 21.3%, 71.2% (sib) DF508 / R117H 20, not done IRT Immunoreactive trypsinogen, FTT failure to thrive, PFT pulmonary function test a Value(s) reported from independent visits of infants with positive CF NBS results has allowed the MA CF NBS program to incorporate communication of relative risk of CF following a positive NBS result that is based upon combined consideration (multi-analyte profiling) of both the IRT concentration and the screening-genotype results. Login to comment

[hide] A new complex allele of the CFTR gene partially ex... Genet Med. 2010 Sep;12(9):548-55. Lucarelli M, Narzi L, Pierandrei S, Bruno SM, Stamato A, d'Avanzo M, Strom R, Quattrucci S
A new complex allele of the CFTR gene partially explains the variable phenotype of the L997F mutation.
Genet Med. 2010 Sep;12(9):548-55., [PMID:20706124]

Abstract [show]
PURPOSE: To evaluate the role of complex alleles, with two or more mutations in cis position, of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in the definition of the genotype-phenotype relationship in cystic fibrosis (CF), and to evaluate the functional significance of the highly controversial L997F CFTR mutation. METHODS: We evaluated the diagnosis of CF or CFTR-related disorders in 12 unrelated subjects with highly variable phenotypes. According to a first CFTR mutational analysis, subjects appeared to be compound heterozygotes for a classic mutation and the L997F mutation. A further CFTR mutational analysis was conducted by means of a protocol of extended sequencing, particularly suited to the detection of complex alleles. RESULTS: We detected a new [R117L; L997F] CFTR complex allele in the four subjects with the highest sweat test values and CF. The eight subjects without the complex allele showed the most varied biochemical and clinical outcome and were diagnosed as having mild CF, CFTR-related disorders, or even no disease. CONCLUSIONS: The new complex allele partially explains the variable phenotype in CF subjects with the L997F mutation. CFTR complex alleles are likely to have a role in the definition of the genotype-phenotype relationship in CF. Whenever apparently identical CFTR-mutated genotypes are found in subjects with divergent phenotypes, an extensive mutational search is mandatory.

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103 In vivo findings and, in some cases, in vitro functional characterizations have been reported for [F508C; S1251N],38 [R347H; D979A],39,40 [R74W; D1270N],41 [G628R; S1235R],42,43 [M470V; S1235R],42 [S912L; G1244V],44 [R117H; (TG)mTn],45-47 [R117C; (TG)mTn],46 [S1235R; (TG)mT5],48 [G576A; R668C],10,49 [V562I; A1006E],49 [R352W; P750L],49 [1198_1203del TGGGCT; 1204GϾA],49 [V754M; CFTRdele3_10,14b_16],50 and [F508del; I1027T].51 These complex alleles have been found in patients with either CF or CFTR-RD, although more often in the former. Login to comment
105 Both in vivo and in vitro studies have also highlighted cases in which there is one main mutation with the phenotypical effect that is worsened by a second mutation, which may even be a neutral variant when isolated, as occurs for F508C,38 R74W,41 S912L,44 and M470V.42 However, different effects have also been described, as in the case of the two M470 and R1235 variants, which give rise to a hyperactive CFTR when present on different alleles but have a suppressive effect when combined on the same allele.42 In addition, the finding of complex alleles in CFTR-RD seems to suggest that a second CFTR mutation may even lead to a partial reversion of the phenotype.43 Indeed, in a reduced number of complex alleles, the effect of the second mutation may partially correct the functional defect, thereby lessening the phenotypical effect, as has been demonstrated for the R553Q mutation in the [F508del; R553Q] complex allele by in vivo52 and in vitro53 studies and for the R553M mutation in the [F508del; R553M] complex allele by an in vitro study.53 A milder phenotypical effect has also been demonstrated for the [R334W; R1158X]54 and [-102T; S549R(TϾG)]55 complex alleles if compared with alleles carrying, respectively, isolated R1158X or S549R(TϾG). Login to comment

[hide] p.Ser1235Arg should no longer be considered as a c... Eur J Hum Genet. 2011 Jan;19(1):36-42. Epub 2010 Aug 18. Rene C, Paulet D, Girodon E, Costa C, Lalau G, Leclerc J, Cabet-Bey F, Bienvenu T, Blayau M, Iron A, Mittre H, Feldmann D, Guittard C, Claustres M, Georges M
p.Ser1235Arg should no longer be considered as a cystic fibrosis mutation: results from a large collaborative study.
Eur J Hum Genet. 2011 Jan;19(1):36-42. Epub 2010 Aug 18., [PMID:20717170]

Abstract [show]
Among the 1700 mutations reported in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, a missense mutation, p.Ser1235Arg, is a relatively frequent finding. To clarify its clinical significance, we collected data from 104 subjects heterozygous for the mutation p.Ser1235Arg from the French CF network, addressed for various indications including classical CF, atypical phenotypes or carrier screening in subjects with or without a family history. Among them, 26 patients (5 having CF, 10 CBAVD (congenital bilateral absence of the vas deferens) and 11 with CF-like symptoms) and 14 healthy subjects were compound heterozygous for a second CFTR mutation. An exhaustive CFTR gene analysis identified a second mutation in cis of p.Ser1235Arg in all CF patients and in 81.8% CBAVD patients. Moreover, epidemiological data from >2100 individuals found a higher frequency of p.Ser1235Arg in the general population than in CF or CBAVD patients. These data, added to the fact that in silico analysis and functional assays suggest a benign nature of this substitution, give several lines of evidence against an association of p.Ser1235Arg with CF or CBAVD.

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175 11 Claustres M, Altieri JP, Guittard C, Templin C, Chevalier-Porst F, Des Georges M: Are p.I148T, p.R74W and p.D1270N cystic fibrosis causing mutations? Login to comment

[hide] [R74W;R1070W;D1270N]: a new complex allele respons... J Cyst Fibros. 2010 Dec;9(6):447-9. Epub 2010 Sep 28. de Prada Merino A, Butschi FN, Bouchardy I, Beckmann JS, Morris MA, Hafen GM, Fellmann F
[R74W;R1070W;D1270N]: a new complex allele responsible for cystic fibrosis.
J Cyst Fibros. 2010 Dec;9(6):447-9. Epub 2010 Sep 28., [PMID:20880762]

Abstract [show]
Since the beginning of population screening for CF carriers, it has become apparent that complex CFTR alleles are not uncommon. Deciphering their impact in disease pathogenesis remains a challenge for both clinicians and researchers. We report the observation of a new complex allele p.[R74W+R1070W+D1270N] found in trans with a type 1 mutation and associated with clinical diagnosis of cystic fibrosis in a one year-old Moroccan patient. This case underlines the difficulties in counseling patients with uncommon mutations and the necessity of functional studies to evaluate the structure-function relationships, since the association of several variations in cis can dramatically alter CFTR function.

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0 Short Communication [R74W;R1070W;D1270N]: A new complex allele responsible for cystic fibrosis Ana de Prada Merinoa , Florence Niel Bütschia , Isabelle Bouchardyb , Jacques S. Beckmanna,c , Michael A. Morrisb , Gaudenz M. Hafend , Florence Fellmanna,⁎ a Service of Medical Genetics, Centre Hospitalier Universitaire Vaudois, 1011 Lausanne, Switzerland b Service of Genetic Medicine, CMU, Geneva University Hospitals, Geneva, Switzerland c Department of Medical Genetics, University of Lausanne, 1011 Lausanne, Switzerland d Department of Paediatrics, Division of Respiratory Medicine, University Hospital of Lausanne, Switzerland Received 4 August 2010; accepted 19 August 2010 Available online 28 September 2010 Abstract Since the beginning of population screening for CF carriers, it has become apparent that complex CFTR alleles are not uncommon. Login to comment
5 Keywords: Complex allele; R74W; D1270N; R1070W; CFTR; Cystic fibrosis 1. Login to comment
9 Since the beginning of population screening for CF carriers, it has become apparent that complex alleles such as [R74W; D1270N] (HGVS nomenclature: c. Login to comment
12 We report the observation of a new complex allele [R74W;R1070W;D1270N] associated with cystic fibrosis in a patient from a Moroccan family. Login to comment
43 Segregation analysis showed the father to be a carrier of 711+1GNT, and the mother of a complex allele [R74W;R1070W;D1270N] (HGVS: c. Login to comment
46 Discussion Here we report a new complex allele [R74W;R1070W; D1270N] in trans with a type I CFTR mutation in a patient with clinical diagnosis of CF and elevated sweat conductivity measurements. Login to comment
55 The double mutant allele [R74W;D1270N], first described in 1995, was originally thought to be deleterious, although considered as a "mild" CFTR mutation responsible for a congenital bilateral absence of the vas deferens (CBAVD) phenotype [7,13]. Login to comment
57 The same authors described the triple mutant [R74W;V201M;D1270N] associated with CBAVD when found in homozygous state or in trans with a severe CF mutation [14]. Login to comment
58 More recently, another group reported healthy male dizygotic twins carrying [R74W; V201M;D1270N] in trans with F508del, suggesting that this complex allele is not associated with classical CF [15]. Login to comment
100 [15] Brugnon F, Bilan F, Heraud MC, Grizard G, Janny L, Creveaux I. Outcome of intracytoplasmic sperm injection for a couple in which the man is carrier of CFTR p.[R74W;V201M;D1270N] and p.841R mutations and his spouse a heterozygous carrier of p.F508del mutation of CFTR gene. Login to comment
98 Are p.1148T, p.R74W and p.D1270N CF causing mutations? Login to comment

[hide] Comprehensive description of CFTR genotypes and ul... Hum Genet. 2011 Apr;129(4):387-96. Epub 2010 Dec 24. de Becdelievre A, Costa C, Jouannic JM, LeFloch A, Giurgea I, Martin J, Medina R, Boissier B, Gameiro C, Muller F, Goossens M, Alberti C, Girodon E
Comprehensive description of CFTR genotypes and ultrasound patterns in 694 cases of fetal bowel anomalies: a revised strategy.
Hum Genet. 2011 Apr;129(4):387-96. Epub 2010 Dec 24., [PMID:21184098]

Abstract [show]
Fetal bowel anomalies may reveal cystic fibrosis (CF) and the search for CF transmembrane conductance regulator (CFTR) gene mutations is part of the diagnostic investigations in such pregnancies, according to European recommendations. We report on our 18-year experience to document comprehensive CFTR genotypes and correlations with ultrasound patterns in a series of 694 cases of fetal bowel anomalies. CFTR gene analysis was performed in a multistep process, including search for frequent mutations in the parents and subsequent in-depth search for rare mutations, depending on the context. Ultrasound patterns were correlated with the genotypes. Cases were distinguished according to whether they had been referred directly to our laboratory or after an initial testing in another laboratory. A total of 30 CF fetuses and 8 cases compatible with CFTR-related disorders were identified. CFTR rearrangements were found in 5/30 CF fetuses. 21.2% of fetuses carrying a frequent mutation had a second rare mutation, indicative of CF. The frequency of CF among fetuses with no frequent mutation was 0.43%. Correlation with ultrasound patterns revealed a significant frequency of multiple bowel anomalies in CF fetuses. The results emphasize the need to search for rearrangements in the diagnosis strategy of fetal bowel anomalies. The diagnostic value of ultrasound patterns combining hyperechogenic bowel, loop dilatation and/or non-visualized gallbladder reveals a need to revise current strategies and to offer extensive CFTR gene testing when the triad is diagnosed, even when no frequent mutation is found in the first-step analysis.

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204 - Born, not CF (no MI) 2 rare CFTR-RD mutations (n 5 1) [R74W;V201M;D1270N]? Login to comment
205 [R74W;V201M;D1270N]a c.[220C[T;601G[A;3808G[A]? Login to comment

[hide] Recommendations for the classification of diseases... J Cyst Fibros. 2011 Jun;10 Suppl 2:S86-102. Bombieri C, Claustres M, De Boeck K, Derichs N, Dodge J, Girodon E, Sermet I, Schwarz M, Tzetis M, Wilschanski M, Bareil C, Bilton D, Castellani C, Cuppens H, Cutting GR, Drevinek P, Farrell P, Elborn JS, Jarvi K, Kerem B, Kerem E, Knowles M, Macek M Jr, Munck A, Radojkovic D, Seia M, Sheppard DN, Southern KW, Stuhrmann M, Tullis E, Zielenski J, Pignatti PF, Ferec C
Recommendations for the classification of diseases as CFTR-related disorders.
J Cyst Fibros. 2011 Jun;10 Suppl 2:S86-102., [PMID:21658649]

Abstract [show]
Several diseases have been clinically or genetically related to cystic fibrosis (CF), but a consensus definition is lacking. Here, we present a proposal for consensus guidelines on cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs), reached after expert discussion and two dedicated workshops. A CFTR-RD may be defined as "a clinical entity associated with CFTR dysfunction that does not fulfil diagnostic criteria for CF". The utility of sweat testing, mutation analysis, nasal potential difference, and/or intestinal current measurement for the differential diagnosis of CF and CFTR-RD is discussed. Algorithms which use genetic and functional diagnostic tests to distinguish CF and CFTR-RDs are presented. According to present knowledge, congenital bilateral absence of vas deferens (CBAVD), acute recurrent or chronic pancreatitis and disseminated bronchiectasis, all with CFTR dysfunction, are CFTR-RDs.

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139 [R74W;V201M;D1270N] and S1235R-IVS8-5T [37,38,66, 68]. Login to comment

[hide] Orphan missense mutations in the cystic fibrosis t... J Mol Diagn. 2011 Sep;13(5):520-7. Epub 2011 Jun 25. Fresquet F, Clement R, Norez C, Sterlin A, Melin P, Becq F, Kitzis A, Thoreau V, Bilan F
Orphan missense mutations in the cystic fibrosis transmembrane conductance regulator a three-step biological approach to establishing a correlation between genotype and phenotype.
J Mol Diagn. 2011 Sep;13(5):520-7. Epub 2011 Jun 25., [PMID:21708286]

Abstract [show]
More than 1860 mutations have been found within the human cystic fibrosis transmembrane conductance regulator (CFTR) gene sequence. These mutations can be classified according to their degree of severity in CF disease. Although the most common mutations are well characterized, few data are available for rare mutations. Thus, genetic counseling is particularly difficult when fetuses or patients with CF present these orphan variations. We describe a three-step in vitro assay that can evaluate rare missense CFTR mutation consequences to establish a correlation between genotype and phenotype. By using a green fluorescent protein-tagged CFTR construct, we expressed mutated proteins in COS-7 cells. CFTR trafficking was visualized by confocal microscopy, and the cellular localization of CFTR was determined using intracellular markers. We studied the CFTR maturation process using Western blot analysis and evaluated CFTR channel activity by automated iodide efflux assays. Of six rare mutations that we studied, five have been isolated in our laboratory. The cellular and functional impact that we observed in each case was compared with the clinical data concerning the patients in whom we encountered these mutations. In conclusion, we propose that performing this type of analysis for orphan CFTR missense mutations can improve CF genetic counseling.

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56 CFTR mutational analysis revealed a complex genotype: p.[Arg74Trp;Val201Met;Asp1270Asn] ϩ [Pro841Arg]. Login to comment
122 Summary of the Patients` Data, Concerning Genotype, Phenotype, and Protein Dysfunction Patient no./sex/age at molecular diagnostics (years) Genotype Phenotype Protein dysfunctions Channel activity* Maturation† Intracellular localization‡ 1/F/3 p.[Leu102Pro] ϩ [Arg553X] Positive sweat test result, bacterial lung colonization, no pancreatitis ϩϩ ϩϩ ϩϩ 2/F/newborn p.[Phe508del] ϩ [Leu167Arg] Positive sweat test result, recurrent pancreatitis, no lung infection ϩϩ ϩϩ ϩϩ 3/F/3 p.[Asn1303Lys] ϩ [Pro574Ser] Normal sweat test result, asymptomatic ϩϩ ϩ ϩ 4/M/31 p.[Arg74Trp;Val201Met; Asp1270Asn] ϩ [Pro841Arg]; c. Login to comment
214 His genotype was p.[Pro841Arg] ϩ [Arg74Trp;Val201Met; Asp1270Asn]. Login to comment
81 Summary of the Patients` Data, Concerning Genotype, Phenotype, and Protein Dysfunction Patient no./sex/age at molecular diagnostics (years) Genotype Phenotype Protein dysfunctions Channel activity* Maturation† Intracellular localization‡ 1/F/3 p.[Leu102Pro] ϩ [Arg553X] Positive sweat test result, bacterial lung colonization, no pancreatitis ϩϩ ϩϩ ϩϩ 2/F/newborn p.[Phe508del] ϩ [Leu167Arg] Positive sweat test result, recurrent pancreatitis, no lung infection ϩϩ ϩϩ ϩϩ 3/F/3 p.[Asn1303Lys] ϩ [Pro574Ser] Normal sweat test result, asymptomatic ϩϩ ϩ ϩ 4/M/31 p.[Arg74Trp;Val201Met; Asp1270Asn] ϩ [Pro841Arg]; c. Login to comment
210 His genotype was p.[Pro841Arg] ϩ [Arg74Trp;Val201Met; Asp1270Asn]. Login to comment

[hide] Complete mutational screening of the CFTR gene in ... Hum Genet. 1998 Dec;103(6):718-22. Bombieri C, Benetazzo M, Saccomani A, Belpinati F, Gile LS, Luisetti M, Pignatti PF
Complete mutational screening of the CFTR gene in 120 patients with pulmonary disease.
Hum Genet. 1998 Dec;103(6):718-22., [PMID:9921909]

Abstract [show]
In order to determine the possible role of the cystic fibrosis transmembrane regulator (CFTR) gene in pulmonary diseases not due to cystic fibrosis, a complete screening of the CFTR gene was performed in 120 Italian patients with disseminated bronchiectasis of unknown cause (DBE), chronic bronchitis (CB), pulmonary emphysema (E), lung cancer (LC), sarcoidosis (S) and other forms of pulmonary disease. The 27 exons of the CFTR gene and their intronic flanking regions were analyzed by denaturing gradient gel electrophoresis and automatic sequencing. Mutations were detected in 11/23 DBE (P = 0.009), 7/25 E, 5/27 CB, 5/26 LC, 5/8 S (P = 0.013), 1/4 tuberculosis, and 1/5 pneumonia patients, and in 5/33 controls. Moreover, the IVS8-5T allele was detected in 6/25 E patients (P = 0.038). Four new mutations were identified: D651N, 2377C/T, E826K, and P1072L. These results confirm the involvement of the CFTR gene in disseminated bronchiectasis of unknown origin, and suggest a possible role for CFTR gene mutations in sarcoidosis, and for the 5T allele in pulmonary emphysema.

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62 Five mutations (G576A, R668C, R74W, R31C, and I506V) are not thought to be the cause of CF (CFGAC website): three of them (G576A, R668C, and R74W) have been found in CBAVD patients (Anguiano et al. 1992; Chillon et al. 1995; Mercier et al. 1995; Verlingue et al. 1996), R31C was described in a DBE patient (Girodon et al. 1997), and I506V was found in the normal allele in the father of a CF child (Ghanem et al. 1994). Login to comment
88 of cases CFTR gene PolyTb status tested mutationa DBE 23 1 G576A-R668C/L997F 7/9 1 ∆F508/L997F 9/9 1 ∆F508/- 7/9 1 R1066C/- 5/7 1 3667ins4/- 5/7 1 R75Q/- 7/7 1 M1137V/- 7/7 1 -/- 5/5 3 -/- 5/7 10 -/- 7/7 2 -/- 7/9 CB 27 1 P111L/- 7/7 1 R117H/- 7/7 1 E585X/- 7/7 1 P1072L/- 7/7 1 -/- 5/7 15 -/- 7/7 6 -/- 7/9 1 -/- 9/9 E 25 1 R668C/- 7/7 6 -/- 5/7 16 -/- 7/7 6 -/- 7/9 S 8 1 E826K/- 7/7 1 ∆F508/- 7/9 1 4382delA/- 7/7 1 L997F/- 7/9 1 V754M/- 7/9 3 -/- 7/7 LC 26 1 I148T/- 5/7 1 D1270N-R74W 5/7 1 D651N/- 7/7 1 Y301C/- 7/7 1 -/- 5/7 16 -/- 7/7 5 -/- 7/9 TB 4 1 -/- 5/7 1 -/- 7/7 2 -/- 7/9 Pneumonia 5 4 -/- 7/7 1 -/- 5/7 Pnx 2 2 -/- 7/7 Controls 68 1 L997F/- 7/9 1 R31C/- 7/7 1 I506V/- 5/7 1 -/- 5/7 1 -/- 5/9 23 -/- 7/7 4 -/- 7/9 1 -/- 9/9 2 ? Login to comment
117 One LC patient had mutations D1270N and R74W, which have been previously described to be syntenic in a CBAVD patient (Mercier et al. 1995). Login to comment
119 Mutation R74W was also syntenic with the 405-46T polymorphism, as previously described (Claustres et al. 1993). Login to comment

[hide] Are p.I148T, p.R74W and p.D1270N cystic fibrosis c... BMC Med Genet. 2004 Aug 2;5:19. Claustres M, Altieri JP, Guittard C, Templin C, Chevalier-Porst F, Des Georges M
Are p.I148T, p.R74W and p.D1270N cystic fibrosis causing mutations?
BMC Med Genet. 2004 Aug 2;5:19., 2004-08-02 [PMID:15287992]

Abstract [show]
BACKGROUND: To contribute further to the classification of three CFTR amino acid changes (p.I148T, p.R74W and p.D1270N) either as CF or CBAVD-causing mutations or as neutral variations. METHODS: The CFTR genes from individuals who carried at least one of these changes were extensively scanned by a well established DGGE assay followed by direct sequencing and familial segregation analysis of mutations and polymorphisms. RESULTS: Four CF patients (out of 1238) originally identified as carrying the p.I148T mutation in trans with a CF mutation had a second mutation (c.3199del6 or a novel mutation c.3395insA) on the p.I148T allele. We demonstrate here that the deletion c.3199del6 can also be associated with CF without p.I148T. Three CBAVD patients originally identified with the complex allele p.R74W-p.D1270N were also carrying p.V201M on this allele, by contrast with non CF or asymptomatic individuals including the mother of a CF child, who were carrying p.R74W-p.D1270N alone. CONCLUSION: These findings question p.I148T or p.R74W-p.D1270N as causing by themselves CF or CBAVD and emphazises the necessity to perform a complete scanning of CFTR genes and to assign the parental alleles when novel missense mutations are identified.

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1 Mireille Claustres*1, Jean-Pierre Altiéri1, Caroline Guittard1, Carine Templin1, Françoise Chevalier-Porst2 and Marie Des Georges1 Address: 1Laboratoire de Génétique Moléculaire, Institut Universitaire de Recherche Clinique et Centre Hospitalier Universitaire, 641 avenue du Doyen Gaston Giraud, 34093 Montpellier, France and 2Laboratoire de Biochimie pédiatrique, Centre Hospitalier Universitaire Paul-Brousse, 69000 Lyon, France Email: Mireille Claustres* - Mireille.Claustres@igh.cnrs.fr; Jean-Pierre Altiéri - Jean-Pierre.Altieri@igh.cnrs.fr; Caroline Guittard - Caroline.Guittard@igh.cnrs.fr; Carine Templin - Carine.Templin@igh.cnrs.fr; Françoise Chevalier-Porst - francoise.chevalier-porst@chu-lyon.fr; Marie Des Georges - Marie.Desgeorges@igh.cnrs.fr * Corresponding author Abstract Background: To contribute further to the classification of three CFTR amino acid changes (p.I148T, p.R74W and p.D1270N) either as CF or CBAVD-causing mutations or as neutral variations. Login to comment
5 Three CBAVD patients originally identified with the complex allele p.R74W-p.D1270N were also carrying p.V201M on this allele, by contrast with non CF or asymptomatic individuals including the mother of a CF child, who were carrying p.R74W-p.D1270N alone. Login to comment
6 Conclusion: These findings question p.I148T or p.R74W-p.D1270N as causing by themselves CF or CBAVD and emphazises the necessity to perform a complete scanning of CFTR genes and to assign the parental alleles when novel missense mutations are identified. Login to comment
19 Moreover, we and others have found that individuals affected with CF or CBAVD carry p.D1270N associated with p.R74W on the same allele [p.R74W;p.D1270N] [10,11,5]. Login to comment
22 These findings provided evidence that these missense changes may not be the true mutations and prompted us to reanalyze all the patients in our CF or CBAVD cohort who had been originally diagnosed as compound heterozygotes for either p.I148T or [p.R74W;p.D1270N] and another mutation on the other allele. Login to comment
29 In this study, we analyzed by DGGE the entire coding and flanking regions of the CFTR gene of individuals who had been previously found to carry p.I148T or the complex allele [p.R74W;p.D1270N] and assayed their relatives for the additional sequence changes identified. Login to comment
48 Triple-mutant allele [p.R74W;p.V201M;p.D1270N] is found in males with CBAVD whereas double-mutant allele [p.R74W;p.D1270N] is found in asymptomatic individuals Re-analysis of the CFTR gene in families carrying [p.R74W;p.D1270N] identified a third mutation (p.V201M) on the same chromosome in three unrelated individuals with CBAVD (table 2). Login to comment
49 Only the double-mutant p.R74W-p.D1270N was present in the two unaffected individuals who were found with these changes in our sample. Login to comment
52 This woman, who was carrying p.P67L on one CFTR gene and [p.R74W-p.D1270N] on the other (table 1), was completely asymptomatic at age 45 years Table 1: CFTR haplotypes associated with mutations found in CF patients carrying p.I148T in cis with c.3395insA or c.3199del6 and in one CF patient carrying c.3199del6 alone Indiv No. Login to comment
72 A CFTR alteration producing a premature termination signal is a class I mutation, considered severe enough to cause CF by itself and exclude the contribution of any other sequence Table 2: CFTR sequence changes found in individuals carrying missense alterations p.R74W, p.D1270N, or p.V201M Mutations Haplotype IVS1 IVS8 IVS8 IVS8 470 IVS17B IVS17B CA CA TGm Tn TA CA CBAVD1 p.R1066C 22 16 11 7 V 30 13 [p.R74W;p.V201M;p.D1270N] 22 16 11 7 V 31 13 CBAVD2 p.M952I 26 17 10 7 M 7 17 [p.R74W;p.V201M;p.D1270N] 22 16 11 7 V 31 13 CBAVD3 [p.R74W;p.V201M;p.D1270N] 22 16 11 7 V 31 13 [p.R74W;p.V201M;p.D1270N] 22 16 11 7 V 31 13 Individual non affected with CF No mutation 21 nd 10 7 M 7 17 [p.R74W;p.D1270N] 22 nd 11 7 V 30 13 Asymptomatic mother of a CF affected girl p.P67L 23 16 10 7 M 7 17 [p.R74;p.D1270N] 22 16 11 7 V 31 13 change on the same allele. Login to comment
76 The complex allele [p.R74W;p.D1270N] may be not enough to cause disease We and others had initially described p.R74W [23] and p.D1270N [24] in isolation but they have since been found in association in many CBAVD or CF patients [10,11] and these two changes were thought to be deleterious, alone or in combination. Login to comment
78 When expressed in HeLa cells, mutant p.R74W, p.D1270N and [p.R74W;p.D1270N] did not affect CFTR processing, however a lower cAMP-responsive anion conductance was observed with the double mutant [p.R74W;p.D1270N] [3]. Login to comment
79 The assay suggested that p.R74W alone should be considered as a polymorphism, p.D1270N alone could generate a CBAVD phenotype while the complex allele could produce a more severe phenotype as p.R74W could enhance the effect of p.D1270N [3]. Login to comment
81 We have found here that a triple-mutant [p.R74W;p.V201M;p.D1270N] allele was carried in all three patients with CBAVD whereas only the double mutant [p.R74W;p.D1270N] allele was present in two asymptomatic individuals including an obligate carrier who was compound heterozygous for a CF mutation. Login to comment
82 Another mother carrying [p.R74W;p.D1270N] in trans of a CF mutation has been described previously; despite two positive sweat tests she was absolutely asymptomatic [25]. Login to comment
85 Although it is not known whether these alleles are associated or not with the third change p.V201M, there are now enough evidence to question the role of the complex allele [p.R74W;p.D1270N] as being a CF or CBAVD mutation. Login to comment
87 Conclusions This report further corroborates the recent hypothesis [9] that p.I148T and p.R74W-p.D1270N may not be true CF/ CBAVD mutations. Login to comment
88 If these observations are further confirmed by a large multicentric study, they will have important implications for genetic counseling of patients and couples found to carry p.I148T or [p.R74W;p.D1270N]. Login to comment

[hide] A neutral variant involved in a complex CFTR allel... Hum Genet. 2005 May;116(6):454-60. Epub 2005 Mar 3. Clain J, Lehmann-Che J, Girodon E, Lipecka J, Edelman A, Goossens M, Fanen P
A neutral variant involved in a complex CFTR allele contributes to a severe cystic fibrosis phenotype.
Hum Genet. 2005 May;116(6):454-60. Epub 2005 Mar 3., [PMID:15744523]

Abstract [show]
In order to further elucidate the contribution of complex alleles to the wide phenotypic variability of cystic fibrosis (CF), we investigated the structure-function relationships of a severe CF-associated complex allele [p.S912L;p.G1244V]. To evaluate the contribution of each mutation to the phenotype, cystic fibrosis transmembrane conductance regulator (CFTR) mutants were expressed in HeLa cells and analysed for protein processing and Cl- channel activity. Both p.G1244V and [p.S912L;p.G1244V] mutants had normal protein processing but markedly decreased Cl- channel activity compared with wild-type. Notably, the double mutant displayed a dramatic decrease in Cl- channel activity compared with p.G1244V (P<0.001). p.S912L had normal protein processing and no detectable impact on CFTR function. In other respects, the p.S912L variation was identified in compound heterozygosity with p.R709X in a healthy fertile man. Together, these data strongly support the view that p.S912L in isolation should be considered as a neutral variant but one that might significantly impair CFTR function when inherited in cis with another CFTR mutation. Our data also further document the contribution of complex alleles to the wide phenotypic variability of CF. The results of functional studies of such complex alleles in other genetic diseases are discussed.

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12 The combination of two missense mutations on the same chromo some has been described clinically to lessen ([p.R553Q;p.F508del], [p.R334W;p.R1158X]; Dork et al. 1991; Duarte et al. 1996) or worsen ([p.R74W;p.D1270N], [p.R347H;p.D979A]; Casals et al. 1995; Hojo et al. 1998) the phenotype of CF patients with regard to the commonest mutation alone (p.F508del, p.R1158X, p.D1270N, p.R347H). Login to comment

[hide] Spectrum of mutations in the CFTR gene in cystic f... Ann Hum Genet. 2007 Mar;71(Pt 2):194-201. Alonso MJ, Heine-Suner D, Calvo M, Rosell J, Gimenez J, Ramos MD, Telleria JJ, Palacio A, Estivill X, Casals T
Spectrum of mutations in the CFTR gene in cystic fibrosis patients of Spanish ancestry.
Ann Hum Genet. 2007 Mar;71(Pt 2):194-201., [PMID:17331079]

Abstract [show]
We analyzed 1,954 Spanish cystic fibrosis (CF) alleles in order to define the molecular spectrum of mutations in the CFTR gene in Spanish CF patients. Commercial panels showed a limited detection power, leading to the identification of only 76% of alleles. Two scanning techniques, denaturing gradient gel electrophoresis (DGGE) and single strand conformation polymorphism/hetroduplex (SSCP/HD), were carried out to detect CFTR sequence changes. In addition, intragenic markers IVS8CA, IVS8-6(T)n and IVS17bTA were also analyzed. Twelve mutations showed frequencies above 1%, p.F508del being the most frequent mutation (51%). We found that eighteen mutations need to be studied to achieve a detection level of 80%. Fifty-one mutations (42%) were observed once. In total, 121 disease-causing mutations were identified, accounting for 96% (1,877 out of 1,954) of CF alleles. Specific geographic distributions for the most common mutations, p.F508del, p.G542X, c.1811 + 1.6kbA > G and c.1609delCA, were confirmed. Furthermore, two other relatively common mutations (p.V232D and c.2789 + 5G > A) showed uneven geographic distributions. This updated information on the spectrum of CF mutations in Spain will be useful for improving genetic testing, as well as to facilitate counselling in people of Spanish ancestry. In addition, this study contributes to defining the molecular spectrum of CF in Europe, and corroborates the high molecular mutation heterogeneity of Mediterranean populations.

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52 Mutation 0.46-0.35 9 c.1078delT #, p.R347P # 8 p.G85V, c.621 + 1G > T #, p.S549R (T > G) #, p.R553X #, c.3849 + 10kbC > T # 7 p.R347H #, c.1812-1G > A, p.R709X 0.30-0.10 6 p.H199Y, p.P205S, 5 p.R117H #, p.G551D #, p.W1089X, p.Y1092X, CFTR50kbdel 4 c.296 + 3insT, c.1717-1G > A #, c.1949del84, c.3849 + 1G > A 3 p.E92K, c.936delTA, c.1717-8G > A, c.1341G > A, p.A561E, c.2603delT, p.G1244E, [p.D1270N; p.R74W] 2 p.Q2X, p.P5L, CFTRdele2,3, p.S50P, p.E60K, c.405 + 1G > A, c.1677delTA, p.L558S, p.G673X, p.R851X, p.Y1014C, p.Q1100P, p.M1101K, p.D1152H, CFTRdele19, p.G1244V, p.Q1281X, p.Y1381X <0,1 1 c.124del23bp, p.Q30X, p.W57X, c.406-1G > A, p.Q98R, p.E115del, c.519delT, p.L159S, c.711 + 3A > T, p.W202X, c.875 + 1G > A, p.E278del, p.W361R, c.1215delG, p.L365P, p.A399D, c.1548delG, p.K536X, p.R560G, c.1782delA, p.L571S, [p.G576A; p.R668C], p.T582R, p.E585X, c.1898 + 1G > A, c.1898 + 3A > G, c.2051delTT, p.E692X, p.R851L, c.2711delT, c.2751 + 3A > G, c.2752-26A > G, p.D924N, p.S945L, c.3121-1G > A, p.V1008D, p.L1065R, [p.R1070W; p.R668C], [p.F1074L; 5T], p.H1085R, p.R1158X, c.3659delC #, c.3667del4, c.3737delA, c.3860ins31, c.3905insT #, c.4005 + 1G > A, p.T1299I, p.E1308X, p.Q1313X, c.4095 + 2T > A, rearrangements study (n = 4) Mutations identified in CF families with mixed European origin: c.182delT, p.L1254X, c.4010del4. Login to comment
67 Seven other complex alleles were observed: [c.296 + 3insT; p.V754M], [p.F508del; p.I1027T], [p.S549R; -102T > A], [p.G576A; p.R668C], [p.R1070W; p.R668C], [p.D1270N; p.R74W] and [p.T1299I; p.I148T]. Login to comment

[hide] UMD-CFTR: a database dedicated to CF and CFTR-rela... Hum Mutat. 2010 Sep;31(9):1011-9. Bareil C, Theze C, Beroud C, Hamroun D, Guittard C, Rene C, Paulet D, Georges M, Claustres M
UMD-CFTR: a database dedicated to CF and CFTR-related disorders.
Hum Mutat. 2010 Sep;31(9):1011-9., [PMID:20607857]

Abstract [show]
With the increasing knowledge of cystic fibrosis (CF) and CFTR-related diseases (CFTR-RD), the number of sequence variations in the CFTR gene is constantly raising. CF and particularly CFTR-RD provide a particular challenge because of many unclassified variants and identical genotypes associated with different phenotypes. Using the Universal Mutation Database (UMD) software we have constructed UMD-CFTR (freely available at the URL: http://www.umd.be/CFTR/), the first comprehensive relational CFTR database that allows an in-depth analysis and annotation of all variations identified in individuals whose CFTR genes have been analyzed extensively. The system has been tested on the molecular data from 757 patients (540 CF and 217 CBAVD) including disease-causing, unclassified, and nonpathogenic alterations (301 different sequence variations) representing 3,973 entries. Tools are provided to assess the pathogenicity of mutations. UMD-CFTR also offers a number of query tools and graphical views providing instant access to the list of mutations, their frequencies, positions and predicted consequences, or correlations between genotypes, haplotypes, and phenotypes. UMD-CFTR offers a way to compile not only disease-causing genotypes but also haplotypes. It will help the CFTR scientific and medical communities to improve sequence variation interpretation, evaluate the putative influence of haplotypes on mutations, and correlate molecular data with phenotypes.

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111 Four variants can be classified into two different categories: p.Phe508Cys (complex allele, mutation), c.1210À12T[5] (mutation, UV), p.Ser1251Asn (complex allele, mutation), p.Arg74Trp (complex allele, UV). Login to comment

[hide] Membrane-integration characteristics of two ABC tr... J Mol Biol. 2009 Apr 17;387(5):1153-64. Epub 2009 Feb 21. Enquist K, Fransson M, Boekel C, Bengtsson I, Geiger K, Lang L, Pettersson A, Johansson S, von Heijne G, Nilsson I
Membrane-integration characteristics of two ABC transporters, CFTR and P-glycoprotein.
J Mol Biol. 2009 Apr 17;387(5):1153-64. Epub 2009 Feb 21., [PMID:19236881]

Abstract [show]
To what extent do corresponding transmembrane helices in related integral membrane proteins have different membrane-insertion characteristics? Here, we compare, side-by-side, the membrane insertion characteristics of the 12 transmembrane helices in the adenosine triphosphate-binding cassette (ABC) transporters, P-glycoprotein (P-gp) and the cystic fibrosis transmembrane conductance regulator (CFTR). Our results show that 10 of the 12 CFTR transmembrane segments can insert independently into the ER membrane. In contrast, only three of the P-gp transmembrane segments are independently stable in the membrane, while the majority depend on the presence of neighboring loops and/or transmembrane segments for efficient insertion. Membrane-insertion characteristics can thus vary widely between related proteins.

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113 For CFTR, we chose mutations located in TM1CFTR (F87L, G91R), TM3CFTR (P205S, L206W), TM4CFTR (C225R), TM5CFTR (DF311, G314E), TM6CFTR (R334L/W, I336K/R/D, I340N/S, L346P, R347L/H), TM8CFTR (S909I, S912L), TM9CFTR (I1005R, A1006E), TM10CFTR (Y1032N), and TM12CFTR (M1137R, ΔM1140, M1140K), or close to the TM region of TM1CFTR (R74W, L102R/P), TMF2CFTR (R117P/L, L137P), and TM11CFTR (M1101K/R). Login to comment
109 For CFTR, we chose mutations located in TM1CFTR (F87L, G91R), TM3CFTR (P205S, L206W), TM4CFTR (C225R), TM5CFTR (DF311, G314E), TM6CFTR (R334L/W, I336K/R/D, I340N/S, L346P, R347L/H), TM8CFTR (S909I, S912L), TM9CFTR (I1005R, A1006E), TM10CFTR (Y1032N), and TM12CFTR (M1137R, ƊM1140, M1140K), or close to the TM region of TM1CFTR (R74W, L102R/P), TMF2CFTR (R117P/L, L137P), and TM11CFTR (M1101K/R). Login to comment

[hide] Retrospective analysis of stored dried blood spots... J Cyst Fibros. 2012 Jul;11(4):332-6. doi: 10.1016/j.jcf.2012.01.001. Epub 2012 Feb 1. Barben J, Gallati S, Fingerhut R, Schoeni MH, Baumgartner MR, Torresani T
Retrospective analysis of stored dried blood spots from children with cystic fibrosis and matched controls to assess the performance of a proposed newborn screening protocol in Switzerland.
J Cyst Fibros. 2012 Jul;11(4):332-6. doi: 10.1016/j.jcf.2012.01.001. Epub 2012 Feb 1., [PMID:22300503]

Abstract [show]
BACKGROUND: Newborn screening (NBS) for Cystic Fibrosis (CF) has been introduced in many countries, but there is no ideal protocol suitable for all countries. This retrospective study was conducted to evaluate whether the planned two step CF NBS with immunoreactive trypsinogen (IRT) and 7 CFTR mutations would have detected all clinically diagnosed children with CF in Switzerland. METHODS: IRT was measured using AutoDELFIA Neonatal IRT-Kit in stored NBS cards. RESULTS: Between 2006 and 2009, 66 children with CF were reported, 4 of which were excluded for various reasons (born in another country, NBS at 6 months, no informed consent). 98% (61/62) had significantly higher IRT compared to matched control group. There was one false negative IRT result in an asymptomatic child with atypical CF (normal pancreatic function and sweat test). CONCLUSIONS: All children but one with atypical CF would have been detected with the planned two step protocol.

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80 CFTR mutations Alleles found Percentage of total Homozygous (n) F508del a 86 68.2 30 3905insT a 4 3.2 1 G542X a 3 2.4 - R553X a 3 2.4 1 W1282X a 2 1.6 - 1717-1 GNA a 2 1.6 - N1303K a 0 0.0 - S549R 3 2.4 1 Q525X 3 2.4 - Y1092X 2 1.6 - 3120+1 GNA b 2 1.6 1 2347delG 2 1.6 - 2176insC 1 0.8 - 3659delC 1 0.8 - 3359delCTCTG 1 0.8 - W1089X 1 0.8 - 711+1 GNT 1 0.8 - D1152H 1 0.8 - G1244E 1 0.8 - R1066C 1 0.8 - R31C 1 0.8 - R347P 1 0.8 - R74W 1 0.8 - S945L 1 0.8 - T501I 1 0.8 - K68X 1 0.8 - Total 126 100.0% 34 a Seven most common CF-gene mutations in Switzerland ("Swiss panel")=79.4% (100/126) of alleles. Login to comment

[hide] Reduced Arylsulfatase B activity in leukocytes fro... Pediatr Pulmonol. 2012 May 1. doi: 10.1002/ppul.22567. Sharma G, Burke J, Bhattacharyya S, Sharma N, Katyal S, Park RL, Tobacman J
Reduced Arylsulfatase B activity in leukocytes from cystic fibrosis patients.
Pediatr Pulmonol. 2012 May 1. doi: 10.1002/ppul.22567., [PMID:22550062]

Abstract [show]
The enzyme Arylsulfatase B (ARSB; N-acetylgalactosamine-4-sulfatase) removes 4-sulfate groups from chondroitin-4-sulfate and dermatan sulfate and is required for the degradation of these sulfated glycosaminoglycans (sGAGs). Since these GAGs accumulate in patients with Cystic Fibrosis (CF), we investigated the activity of ARSB in leukocytes of patients with CF, to consider if reduced activity of ARSB might contribute to the pathophysiology of CF. Previous cell-based experiments had demonstrated that when the deficiency of the cystic fibrosis transmembrane regulator (CFTR) was corrected in bronchial epithelial cells, the ARSB activity increased significantly. De-identified, citrated blood samples were collected from 16 children with CF and 31 control subjects, seen in the Pediatric Clinic at Rush University Medical Center. Polymorphonuclear leukocytes (PMN) and mononuclear cell (MC) populations were separated by density gradient, and blinded determinations of ARSB activity were performed using the exogenous substrate 4-methylumbilliferyl sulfate. Interleukin-6 was measured in the plasma samples by ELISA. ARSB activity was significantly less in the PMN and MC from the CF patients than controls (P < 0.0001, unpaired t-test, two-tailed). Interleukin-6 levels in plasma were significantly greater in the CF population (P < 0.001). Mean age, age range, and male:female ratio of CF patients and controls were similar, and no association of ARSB activity with age, gender, or CFTR genotype was evident. Since recombinant human ARSB is used successfully for replacement therapy in Mucopolysaccharidosis VI, it may be useful to restore ARSB activity to normal levels and increase degradation of sulfated GAGs in CF patients. Pediatr Pulmonol. (c) 2012 Wiley Periodicals, Inc.

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66 TABLE 2- Subject Data Gender Age (yrs) PMN ARSBa (nmol/mg protein/hr) MC ARSBb (nmol/mg protein/hr) WBC ARSBc (nmol/mg protein/hr) IL-6d (pg/ml) Other Cystic fibrosis Male 10.5 52.3 44.7 63.9 DF508/DF508 Female 6.5 48.4 63.8 DF508/DF508 Male 14.5 52.0 46.2 66.6 DF508/G551D Female 9 44.1 50.9 60.8 2307insA/3120 þ 1G > A Female 17.5 49.8 53.7 73.8 NAe Male 17.5 57.1 53.0 73.8 DF508/DF508 Female 15.5 46.0 61.3 DF508/1717-1G > A Male 6.5 52.1 68.6 DF508/DF508 Male 16.5 53.6 52.2 66.2 DF508/DF508 Female 9 60.2 53.7 66.8 S1255x(2)/11203V(2) Female 15 42.9 69.4 DF508/DF508 Male 17 50.1 58.1 64.3 R74W/D1270N/(TG)11-5T/(TG)11-7T Female 9 44.4 48.0 58.2 DF508/DF508 Male 8.5 59.7 48.7 65.2 DF508/312011G > A Female 10.5 53.8 58.3 75.1 DF508/312011G > A Male 15 45.5 48.2 50.0 F508del/P74W/D1270N/P798S/G921E Controls Female 5 67.4 66.4 4.8 Neuromuscular Female 4.5 72.7 64.8 5.1 Down Syndrome Female 17 71.7 60.2 4.3 Down Syndrome; renal Male 3.5 83.8 63.6 4.4 Neuromuscular Male 12 71.0 67.6 4.6 Trauma Male 16 68.8 59.4 5.8 Neuromuscular Male 7 82.8 59.4 - Heme/Onc Male 17 78.7 55.8 5.3 Renal Female 16.5 76.9 65.2 4.1 Renal Male 12.5 69.7 66.6 6.3 Renal Male 8 78.0 56.2 5.0 None Female 8 69.6 67.9 5.6 None Female 5 66.8 64.0 4.8 None Female 11 77.9 68.6 5.8 None Male 14 85.5 61.2 5.0 None Female 9 77.6 65.3 5.0 None Female 16 67.4 64.0 5.0 None Female 9 75.9 57.4 4.7 None Male 16 81.9 58.8 5.4 None Male 14 81.3 69.1 6.2 None Male 15.5 73.0 62.9 3.6 None Male 7.5 73.9 57.2 13.5 Asthma Male 11 62.5 69.9 18.2 Asthma Female 11 70.1 65.3 13.8 Asthma Female 8.5 81.3 56.8 11.4 Asthma Male 9 53.1 55.6 12.2 Asthma Male 3.5 60.0 47.6 17.8 Asthma Male 5.5 68.6 39.0 13.0 Asthma Male 12 84.4 45.8 24.9 Asthma Male 12 68.1 51.4 26.6 Asthma Male 16.5 56.3 47.8 26.6 Asthma a for polymorphonuclear leukocyte arylsulfatase B activity. Login to comment

[hide] Pancreas divisum is not a cause of pancreatitis by... Am J Gastroenterol. 2012 Feb;107(2):311-7. doi: 10.1038/ajg.2011.424. Epub 2011 Dec 13. Bertin C, Pelletier AL, Vullierme MP, Bienvenu T, Rebours V, Hentic O, Maire F, Hammel P, Vilgrain V, Ruszniewski P, Levy P
Pancreas divisum is not a cause of pancreatitis by itself but acts as a partner of genetic mutations.
Am J Gastroenterol. 2012 Feb;107(2):311-7. doi: 10.1038/ajg.2011.424. Epub 2011 Dec 13., [PMID:22158025]

Abstract [show]
OBJECTIVES: The role of pancreas divisum (PD) as a cause of acute recurrent or chronic pancreatitis (AR/CP) is still a matter of debate. METHODS: The aims of this study were to evaluate the frequency of PD diagnosed using magnetic resonance cholangiopancreatography (MRCP) in patients with AR/CP of unknown origin (n=40) after careful exclusion of all known causes and to test the hypothesis of an interaction between anatomical (PD) and functional genetic anomalies (SPINK1, PRSS1, or CFTR gene mutations or polymorphisms (n=19, 25, and 30, respectively)) that could result in AR/CP. Patients with alcohol-induced pancreatitis (n=29) and subjects who had MRCP for a nonpancreatic disease (n=45) served as controls. RESULTS: PD frequency was 7% in subjects without pancreatic disease, 7% in patients with alcohol-induced pancreatitis, and 5, 16, 16, and 47% in those with idiopathic, and PRSS1-, SPINK1-, and CFTR-associated pancreatitis, respectively (P<0.0001). There was no significant difference between idiopathic pancreatitis and the two control groups. The frequency of PD was higher in patients with CFTR gene-associated pancreatitis as compared with those with idiopathic and alcoholic pancreatitis (P<0.0001) and with those with SPINK1 and PRSS1 gene-associated pancreatitis (P<0.02). CONCLUSIONS: The frequency of PD was not different in patients with idiopathic pancreatitis as compared with controls, demonstrating that PD by itself is not a cause of pancreatitis. PD frequency was higher in patients with genetic pancreatitis, especially in those with CFTR mutations or polymorphisms, suggesting a cumulative effect of these two cofactors.

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48 We defined three groups of patients: (i) common CF mutations called CFcom, previously identified in patients with classic CF with or without pancreatic insufficiency (such as p.F508del, p.W1282, and so on…); (ii) uncommon CF mutations causing variable phenotype called CFunc, previously identified in patients with CFTR-related disease such as bilateral absence of the vas deferens, disseminated bronchiectasis, and pancreatitis (p.R74W-D1270N, IVS8-5T, and so on…); and (iii) variants of unknown significance called CFvus, considered to be polymorphisms on the basis of linkage analysis and their frequency in normal individuals, but which may alter the CFTR protein function in a minor way (such as 1716G>A (p.E528E), p.R75Q…) (www.genet.sickkids.on.ca/cftr/app) (34). Login to comment

[hide] Extensive molecular analysis of patients bearing C... J Mol Diagn. 2012 Jan;14(1):81-9. Epub 2011 Oct 20. Amato F, Bellia C, Cardillo G, Castaldo G, Ciaccio M, Elce A, Lembo F, Tomaiuolo R
Extensive molecular analysis of patients bearing CFTR-related disorders.
J Mol Diagn. 2012 Jan;14(1):81-9. Epub 2011 Oct 20., [PMID:22020151]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs) may present with pancreatic sufficiency, normal sweat test results, and better outcome. The detection rate of mutations is lower in CFTR-RD than in classic CF: mutations may be located in genes encoding proteins that interact with CFTR or support channel activity. We tested the whole CFTR coding regions in 99 CFTR-RD patients, looking for gene mutations in solute carrier (SLC) 26A and in epithelial Na channel (ENaC) in 33 patients who had unidentified mutations. CFTR analysis revealed 28 mutations, some of which are rare. Of these mutations, RT-PCR demonstrated that the novel 1525-1delG impairs exon 10 splicing; by using minigene analysis, we excluded the splicing effect of three other novel intronic variants. Analysis of SLC26A genes revealed several variants, some of which are novel, that did not affect mRNA expression. Other mutations occurred in the ENaC genes encoding the ENaC subunits, but their frequency did not significantly differ between patients and controls. Our data, although obtained on a preliminary cohort of CFTR-RD patients, exclude a role of mutations in SLC26A and in SCNN genes in the pathogenesis of such disease; we confirm that CFTR analysis has a relevant role in CFTR-RD patients; and it appears mandatory to use CFTR scanning techniques and approaches to reveal the effect of novel mutations.

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89 In one CBAVD patient, 1525-1delG was in cis with the R74W variant and the other chromosome carried the G1244E mutation. Login to comment
156 On the other hand, the known 1525-1GϾA mutation that involves the same nucleotide also causes the activation of novel splicing sites within exon 10.18 A CBAVD patient had a complex genotype (ie, G1244E, R74W, and 1525-1delG), the latter in cis with R74W. Login to comment
157 The R74W mutation was originally considered a disease-causing mutation (http://www.genet.sickkids.on.ca), but more recently, it was classified as a sequence variation with no phenotypic effect if present alone, whereas the D1270N mutation, frequently observed in cis with R74W, acts as a mutation even if this point is controversial.36 We did not find D1270N in our patient, who instead carried 1525-1delG in cis with R74W. Login to comment

[hide] Borderline sweat test: Utility and limits of genet... Clin Biochem. 2009 May;42(7-8):611-6. Epub 2009 Jan 24. Seia M, Costantino L, Paracchini V, Porcaro L, Capasso P, Coviello D, Corbetta C, Torresani E, Magazzu D, Consalvo V, Monti A, Costantini D, Colombo C
Borderline sweat test: Utility and limits of genetic analysis for the diagnosis of cystic fibrosis.
Clin Biochem. 2009 May;42(7-8):611-6. Epub 2009 Jan 24., [PMID:19318035]

Abstract [show]
OBJECTIVE: The sweat test remains the gold standard for the diagnosis of Cystic Fibrosis (CF) even despite the availability of molecular analysis of Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR). We investigated the relationship between CFTR mutation analysis and sweat chloride concentration in a cohort of subjects with borderline sweat test values, in order to identify misdiagnosis of CF. DESIGN AND METHODS: In the period between March 2006 and February 2008 we performed 773 sweat tests in individuals referred for suspect CF. Ninety-one subjects had chloride values in the border-line range. Clinicians required CFTR gene complete scanning on 66 of them. RESULTS: The mean value of sweat chloride in the DNA negative subjects was lower than in those with at least one CFTR mutation. Our data indicate that 39 mEq/l is the best sensitivity trade off for the sweat test with respect to genotype. CONCLUSIONS: To optimise diagnostic accuracy of reference intervals, it may be useful to modify from 30 to 39 mEq/l the threshold for sweat chloride electrolytes.

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59 In order to evaluate the relationship between the presence of CFTR mutation and sweat chloride concentration, we focused our attention on the 91 individuals (11.8%) in whom borderline sweat chloride values (31-59 mEq/l) were recorded (mean sweat electrolyte value was 40.0 mEq/l): 25 refused to be referred to the local Table 2 Demographic and clinical features of subjects with positive DNA analysis Patient Initials Gender Age at test years/ months Sweat chloride mEq/l Clinical indication DNA results IRT Right arm Left arm 1 CA M 49y5m 34 34 CBAVD G542X/5T-TG12 ND 2 SA M 45y2m 45 43 Pancreatitis F508del/R117H-7T ND 3 PD F 43y7m 33 38 Recurrent bronchitis F508del/5T-TG12 ND 4 CA M 36y1m 31 29 CBAVD R117H-7T/R117C-7T ND 5 SC M 36y1m 33 40 Pneumonia F508del/D1152H ND 6 MG M 25Y5m 41 45 CBAVD Q552X/D1152H NEG 7 SG M 18y5m 49 54 Pancreatitis 4016insT/dupl.prom.-3 ND 8 LS F 10y4m 41 38 Pancreatitis D1152H/L997F NEG 9 CM M 8y3m 30 31 Pneumonia F1052V/A120T NEG 10 PT M 7y3m 41 39 Positive screening F508del/Y1032C POS 11 ME F 7y1m 44 44 Positive screening 2789+5GNA/5T-TG12 POS 12 PM F 6y4m 35 36 Positive screening 2183AANG/5T-TG12 POS 13 BM F 6y3m 36 39 Positive screening F508del/5T-TG12 POS 14 CD M 5y8m 40 41 Chronic bronchitis 5T-TG12/5T-TG12 NEG 15 CG F 4y5m 33 37 Recurrent bronchitis R553X/L997F POS 16 CS F 3y8m 53 58 Family history G542X/D614G POS 17 VA M 4y2m 49 43 Pneumonia E831X/5T-TG12 ND 18 SC M 3y4m 39 39 Positive screening R352Q/G213E POS 19 CC F 2y3m 31 31 Positive screening F508del/5T-TG12 POS 20 CA F 2y5m 51 52 Recurrent bronchitis E831X/5T-TG12 ND 21 MR F 3y+7m 29 31 Family history G542X/5T-TG12 POS 22 CM F 2y3m 60 58 Pneumonia T338I/L997F POS 23 LM F 2y1m 50 52 Positive screening F508del/E1473X POS 24 CGE F 0y8m 46 47 Positive screening E92K/5T-TG13 POS 25 NF M 0y7m 32 30 Positive screening F508del/P5L POS 26 RG M 0y7m 45 40 Positive screening N1303K/P5L POS 27 PE M 47y4m 60 58 Nasal polyposis R1066H/UN ND 28 LS M 39y9m 39 38 Azoospermy N1303K/UN ND 29 TM M 38y4m 40 45 Azoospermy N1303K/UN ND 30 DF M 34y2m 52 58 Bronchiectasis 3849+10 kbCNT/UN ND 31 TV F 30y5m 35 34 Recurrent bronchitis L997F/UN ND 32 FA F 18y7m 53 49 Family history Del es.2/UN NEG 33 DG M 17y8m 43 47 Recurrent bronchitis 5T-TG12/UN NEG 34 LN F 13y7m 54 53 Nasal poliposis, malnutrition R74W-V855I/UN NEG 35 FKT M 15y4m 54 53 Chronic bronchitis R352Q/UN NEG 36 BM M 10y9m 48 51 Chronic bronchitis T1263I/UN NEG 37 SV F 11y1m 60 58 Chronic bronchitis R347H/UN NEG 38 CV F 10y10m 38 39 Recurrent bronchitis 5T-TG12/UN NEG 39 BF F 9y10m 37 38 Chronic bronchitis L997F/UN NEG 40 CA M 8y2m 33 32 Pneumonia F508del/UN NEG 41 RX F 8y7m 29 31 Chronic bronchitis V920L/UN NEG 42 MG F 4y3m 51 51 Positive screening F508del/UN POS Sweat chloride concentration and mutations/variants detected are also reported. Login to comment
57 In order to evaluate the relationship between the presence of CFTR mutation and sweat chloride concentration, we focused our attention on the 91 individuals (11.8%) in whom borderline sweat chloride values (31-59 mEq/l) were recorded (mean sweat electrolyte value was 40.0 mEq/l): 25 refused to be referred to the local Table 2 Demographic and clinical features of subjects with positive DNA analysis Patient Initials Gender Age at test years/ months Sweat chloride mEq/l Clinical indication DNA results IRT Right arm Left arm 1 CA M 49y5m 34 34 CBAVD G542X/5T-TG12 ND 2 SA M 45y2m 45 43 Pancreatitis F508del/R117H-7T ND 3 PD F 43y7m 33 38 Recurrent bronchitis F508del/5T-TG12 ND 4 CA M 36y1m 31 29 CBAVD R117H-7T/R117C-7T ND 5 SC M 36y1m 33 40 Pneumonia F508del/D1152H ND 6 MG M 25Y5m 41 45 CBAVD Q552X/D1152H NEG 7 SG M 18y5m 49 54 Pancreatitis 4016insT/dupl.prom.-3 ND 8 LS F 10y4m 41 38 Pancreatitis D1152H/L997F NEG 9 CM M 8y3m 30 31 Pneumonia F1052V/A120T NEG 10 PT M 7y3m 41 39 Positive screening F508del/Y1032C POS 11 ME F 7y1m 44 44 Positive screening 2789+5GNA/5T-TG12 POS 12 PM F 6y4m 35 36 Positive screening 2183AANG/5T-TG12 POS 13 BM F 6y3m 36 39 Positive screening F508del/5T-TG12 POS 14 CD M 5y8m 40 41 Chronic bronchitis 5T-TG12/5T-TG12 NEG 15 CG F 4y5m 33 37 Recurrent bronchitis R553X/L997F POS 16 CS F 3y8m 53 58 Family history G542X/D614G POS 17 VA M 4y2m 49 43 Pneumonia E831X/5T-TG12 ND 18 SC M 3y4m 39 39 Positive screening R352Q/G213E POS 19 CC F 2y3m 31 31 Positive screening F508del/5T-TG12 POS 20 CA F 2y5m 51 52 Recurrent bronchitis E831X/5T-TG12 ND 21 MR F 3y+7m 29 31 Family history G542X/5T-TG12 POS 22 CM F 2y3m 60 58 Pneumonia T338I/L997F POS 23 LM F 2y1m 50 52 Positive screening F508del/E1473X POS 24 CGE F 0y8m 46 47 Positive screening E92K/5T-TG13 POS 25 NF M 0y7m 32 30 Positive screening F508del/P5L POS 26 RG M 0y7m 45 40 Positive screening N1303K/P5L POS 27 PE M 47y4m 60 58 Nasal polyposis R1066H/UN ND 28 LS M 39y9m 39 38 Azoospermy N1303K/UN ND 29 TM M 38y4m 40 45 Azoospermy N1303K/UN ND 30 DF M 34y2m 52 58 Bronchiectasis 3849+10 kbCNT/UN ND 31 TV F 30y5m 35 34 Recurrent bronchitis L997F/UN ND 32 FA F 18y7m 53 49 Family history Del es.2/UN NEG 33 DG M 17y8m 43 47 Recurrent bronchitis 5T-TG12/UN NEG 34 LN F 13y7m 54 53 Nasal poliposis, malnutrition R74W-V855I/UN NEG 35 FKT M 15y4m 54 53 Chronic bronchitis R352Q/UN NEG 36 BM M 10y9m 48 51 Chronic bronchitis T1263I/UN NEG 37 SV F 11y1m 60 58 Chronic bronchitis R347H/UN NEG 38 CV F 10y10m 38 39 Recurrent bronchitis 5T-TG12/UN NEG 39 BF F 9y10m 37 38 Chronic bronchitis L997F/UN NEG 40 CA M 8y2m 33 32 Pneumonia F508del/UN NEG 41 RX F 8y7m 29 31 Chronic bronchitis V920L/UN NEG 42 MG F 4y3m 51 51 Positive screening F508del/UN POS Sweat chloride concentration and mutations/variants detected are also reported. Login to comment

[hide] Outcome of intracytoplasmic sperm injection for a ... Fertil Steril. 2008 Nov;90(5):2004.e23-6. Epub 2008 Aug 13. Brugnon F, Bilan F, Heraud MC, Grizard G, Janny L, Creveaux I
Outcome of intracytoplasmic sperm injection for a couple in which the man is carrier of CFTR p.[R74W;V201M;D1270N] and p.P841R mutations and his spouse a heterozygous carrier of p.F508del mutation of the cystic fibrosis transmembrane conductance regulator gene.
Fertil Steril. 2008 Nov;90(5):2004.e23-6. Epub 2008 Aug 13., [PMID:18703181]

Abstract [show]
OBJECTIVE: To document the phenotype associated with the p.[R74W;V201M;D1270N] and p.P841R mutations of cystic fibrosis transmembrane conductance regulator (CFTR) gene. DESIGN: Case report. SETTING: Biology and medicine of reproduction in a university hospital. PATIENT(S): A couple in which the man is carrier of the triple mutant p.[R74W;V201M;D1270N] allele in trans to p.P841R mutation and his spouse a heterozygous carrier for the severe p.F508del mutation of the CFTR gene, who became pregnant after intracytoplasmic sperm injection (ICSI) with twins. INTERVENTION(S): Genetic counseling; CFTR gene sequencing; ICSI; children's follow-up. MAIN OUTCOME MEASURE(S): First report of a male phenotype associated with the p.P841R mutation. RESULT(S): The triple mutant p.[R74W;V201M;D1270N] allele associated with the unknown p.P841R mutations were detected in this man with congenital bilateral absence of the vas deferens, which may presume p.P841R as a severe mutation. After genetic counseling, the couple preferred prenatal diagnosis after ICSI than preimplantation genetic diagnosis, which revealed that the boys were both carriers of p.[R74W;V201M;D1270N] and p.F508del mutations. They are now 4 years old and show normal growth without nutritional deficiency. CONCLUSION(S): This case report documents for the first time a male phenotype associated with the p.P841R mutation and underlines the difficulties in counseling a man with congenital bilateral absence of the vas deferens carrying uncommon mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene before ICSI.

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0 CASE REPORT Outcome of intracytoplasmic sperm injection for a couple in which the man is carrier of CFTR p.[R74W;V201M;D1270N] and p.P841R mutations and his spouse a heterozygous carrier of p.F508del mutation of the cystic fibrosis transmembrane conductance regulator gene Florence Brugnon, M.D.,a Frederic Bilan, Ph.D.,b Marie-Christine Heraud, M.D.,c Genevieve Grizard, Ph.D.,a Laurent Janny, M.D.,a and Isabelle Creveaux, M.D., Ph.Dd a CHU Clermont-Ferrand, Biologie du Developpement et de la Reproduction, CECOS, H^otel Dieu, Clermont Ferrand; b CHU Poitiers, Laboratoire de Genetique Cellulaire et Moleculaire, Universite de Poitiers, UFR Medecine-Pharmacie, Poitiers; c CHU Clermont Ferrand, Pediatrie A, H^otel Dieu; and d CHU Clermont Ferrand, Laboratoire de biochimie medicale et biologie moleculaire, Faculte de Medecine, Clermont Ferrand, France Objective: To document the phenotype associated with the p.[R74W;V201M;D1270N] and p.P841R mutations of cystic fibrosis transmembrane conductance regulator (CFTR) gene. Login to comment
3 Patient(s): A couple in which the man is carrier of the triple mutant p.[R74W;V201M;D1270N] allele in trans to p.P841R mutation and his spouse a heterozygous carrier for the severe p.F508del mutation of the CFTR gene, who became pregnant after intracytoplasmic sperm injection (ICSI) with twins. Login to comment
6 Result(s): The triple mutant p.[R74W;V201M;D1270N] allele associated with the unknown p.P841R mutations were detected in this man with congenital bilateral absence of the vas deferens, which may presume p.P841R as a severe mutation. Login to comment
7 After genetic counseling, the couple preferred prenatal diagnosis after ICSI than preimplantation genetic diagnosis, which revealed that the boys were both carriers of p.[R74W;V201M;D1270N] and p.F508del mutations. Login to comment
12 Key Words: CFTR, [p.R74W;p.V201M;p.1270N], p.P841R, genetic counseling, ICSI, CBAVD Treatment by assisted reproductive technology (ART) of infertile men with congenital bilateral absence of the vas deferens (CBAVD) associated with mutations of the CFTR gene changed after the introduction of intracytoplasmic sperm injection (ICSI) with epididymal or testicular spermatozoa (1). Login to comment
16 The purpose of this case report is to describe and analyze the outcome of an infertile couple in which the man with CBAVD is carrier of rare mutations of the CFTR gene p.[R74W;V201M;D1270N] þ p.P841R and his spouse, a heterozygous carrier for F508del. Login to comment
27 doi:10.1016/j.fertnstert.2008.05.057 2004.e23 p.[R74W;V201M;D1270N] allele was previously reported in men with CBAVD (3), but never in symptomatic patients with CF. Login to comment
40 Results revealed that the man was a compound heterozygous carrier of the triple mutant p.[R74W;V201M;D1270N] allele and the unknown p.P841R mutation (Fig. Login to comment
42 Segregation analysis of the man`s parents revealed that his father transmitted the CFTR p.P841R mutation and his mother, the complex allele p.[R74W;V201M;D1270N]. Login to comment
49 At 22 weeks gestation, prenatal diagnosis revealed that the two male fetuses carried not only the triple mutant allele p.[R74W;V201M;D1270N] inherited from their father but also p.F508del from their mother. Login to comment
53 Electrophoregrams of the sequencing products obtained in the patient showing heterozygous profiles for the p.D1270N, p.R74W, and the newly identified p.841R mutations (indicated by red arrow in each figure). Login to comment
54 (a) p.D1270N mutation (3940 G>A); (b) p.R74W mutation (352 C>T); (c) p.P841R mutation (2854 C>G). Login to comment
70 The CBAVD phenotype of this infertile patient could indicate that this mutation may be severe or mild, as the triple mutant p.[R74W;V201M;D1270N] is considered as a mild one, and as it was described in CBAVD patients in trans with severe mutations. Login to comment
73 Thus p.D1270N was found more frequently (6) in carrier screening than in patients with CF (frequency 14% vs. 0.068%). Login to comment
74 Initially p.R74W and p.D1270N were described in isolation but they have since been found in association in many men with CBAVD (3, 7). Login to comment
75 Structure function analysis demonstrated that when they are expressed in HeLa cells; mutants p.R74W, p.D1270N, and p.[R74W;D1270N] do not affect CFTR processing.However,lowercyclicadenosine30 :50 monophosphate (cAMP) responsive anion conductance was observed with the double mutant p.[R74W;D1270N]. Login to comment
76 This study suggested that mutant p.R74Walone could be considered as a polymorphism, p.D1270N alone could generate a CBAVD phenotype, whereas the complex allele p.[R74W;D1270N] may produce a more severe phenotype because p.R74W could enhance the effect of p.D1270N (8). Login to comment
78 Compound heterozygote for p.D1270N has been identified in asymptomatic adults (6), whereas individuals carrying p.D1270N associated with p.R74W on the same allele (p.[R74W;D1270N]) have not been found among asymptomatic (3) or among men with CBAVD (7). Login to comment
80 The alteration found for our patient is a triple mutant allele p.[R74W;V201M;D1270N]. Login to comment
82 The CBAVD phenotype described in homozygous p.[R74W;V201M;D1270N] patients (3) suggests that we can consider this triple mutant allele as mild. Login to comment
84 During genetic counseling before ICSI, the couple was given explanations concerning the high risk of CF for the children if both p.F508del and p.P841R were inherited, respectively, from their mother and father, and the risk of CBAVD if p.[R74W;V201M;D1270N] and p.F508del were inherited. Login to comment
91 Because the twin boys are carriers of this complex association of mutations and that the double complex allele p.[R74W;D1270N] associated with p.F508del has been described before as being associated with a pauci-symptomatic form of CF (9), they are monitored regularly. Login to comment
26 Fertility and Sterility Vol. 90, No. 5, November 2008 0015-0282/08/$34.00 Copyright &#aa;2008 American Society for Reproductive Medicine, Published by Elsevier Inc. doi:10.1016/j.fertnstert.2008.05.057 2004.e23 p.[R74W;V201M;D1270N] allele was previously reported in men with CBAVD (3), but never in symptomatic patients with CF. Login to comment
39 Results revealed that the man was a compound heterozygous carrier of the triple mutant p.[R74W;V201M;D1270N] allele and the unknown p.P841R mutation (Fig. 1) and his spouse was a heterozygous carrier for p.F508del. Login to comment
47 At 22 weeks gestation, prenatal diagnosis revealed that the two male fetuses carried not only the triple mutant allele p.[R74W;V201M;D1270N] inherited from their father but also p.F508del from their mother. Login to comment
51 Electrophoregrams of the sequencing products obtained in the patient showing heterozygous profiles for the p.D1270N, p.R74W, and the newly identified p.841R mutations (indicated by red arrow in each figure). Login to comment
52 (a) p.D1270N mutation (3940 G>A); (b) p.R74W mutation (352 C>T); (c) p.P841R mutation (2854 C>G). Login to comment
68 The CBAVD phenotype of this infertile patient could indicate that this mutation may be severe or mild, as the triple mutant p.[R74W;V201M;D1270N] is considered as a mild one, and as it was described in CBAVD patients in trans with severe mutations. Login to comment
72 Initially p.R74W and p.D1270N were described in isolation but they have since been found in association in many men with CBAVD (3, 7). Login to comment
89 Because the twin boys are carriers of this complex association of mutations and that the double complex allele p.[R74W;D1270N] associated with p.F508del has been described before as being associated with a pauci-symptomatic form of CF (9), they are monitored regularly. Login to comment

[hide] Validation of high-resolution DNA melting analysis... J Mol Diagn. 2008 Sep;10(5):424-34. Epub 2008 Aug 7. Audrezet MP, Dabricot A, Le Marechal C, Ferec C
Validation of high-resolution DNA melting analysis for mutation scanning of the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
J Mol Diagn. 2008 Sep;10(5):424-34. Epub 2008 Aug 7., [PMID:18687795]

Abstract [show]
High-resolution melting analysis of polymerase chain reaction products for mutation scanning, which began in the early 2000s, is based on monitoring of the fluorescence released during the melting of double-stranded DNA labeled with specifically developed saturation dye, such as LC-Green. We report here the validation of this method to scan 98% of the coding sequence of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We designed 32 pairs of primers to amplify and analyze the 27 exons of the gene. Thanks to the addition of a small GC-clamp at the 5' ends of the primers, one single melting domain and one identical annealing temperature were obtained to co-amplify all of the fragments. A total of 307 DNA samples, extracted by the salt precipitation method, carrying 221 mutations and 21 polymorphisms, plus 20 control samples free from variations (confirmed by denaturing high-performance liquid chromatography analysis), was used. With the conditions described in this study, 100% of samples that carry heterozygous mutations and 60% of those with homozygous mutations were identified. The study of a cohort of 136 idiopathic chronic pancreatitis patients enabled us to prospectively evaluate this technique. Thus, high-resolution melting analysis is a robust and sensitive single-tube technique for screening mutations in a gene and promises to become the gold standard over denaturing high-performance liquid chromatography, particularly for highly mutated genes such as CFTR, and appears suitable for use in reference diagnostic laboratories.

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171 Results of CFTR Analysis by HRM on 136 Samples of Patients with Idiopathic Chronic Pancreatitis (ICP) Exon Number of positive samples Mutations identified Variants identified New positive controls 1 14 14 125GϾC 2 1 1 R31C 3 9 1 G85E 7 R75Q 1 R74W 4 4 1 R117G 1 I148T R117G 1 R117H 1 A120T 5 1 1 L188P L188P 6a 5 1 V201M 1 A221A A221A 3 875ϩ40 AϾG 6b 27 1 M284T 26 1001ϩ11CϾT M284T 7 1 1 L320V L320V 8 0 0 9 1 1 D443Y 10 16 8 F508del 8 E528E 11 1 1 G542X 12 6 4 G576A 1 Y577Y L568F 1 L568F 13 7 1 S737F 4 R668C S737F 1 V754M L644L 1 L644L 14a 53 52 T854T T854TϩI853I 1 T854TϩI853I 14b 0 0 15 3 1 L967S T908S 1 T908S 1 S945L 16 0 0 17a 10 7 L997F 1 3271ϩ18CϾT 3271 ϩ 3AϾG 1 3271 ϩ 3 AϾG 1 Y1014C 17b 3 1 L1096L L1096L 1 H1054DϩG1069R 1 3272-33AϾG H1054DϩG1069R 3272-33AϾG 18 2 1 D1152H E1124del 1 E1124del 19 5 5 S1235R poly 20 7 1 W1282X 5 P1290P 1 D1270N 21 2 1 N1303K 1 T1299T 22 0 0 23 1 0 4374ϩ13 AϾG 24 43 40 Q1463Q 2 Y1424Y 1 Q1463QϩY1024Y ing domain of a gene brings an excellent sensitivity for heterozygote detection that is very close to 100%. Login to comment

[hide] CFTR mutations in the Algerian population. J Cyst Fibros. 2008 Jan;7(1):54-9. Epub 2007 Jun 14. Loumi O, Ferec C, Mercier B, Creff J, Fercot B, Denine R, Grangaud JP
CFTR mutations in the Algerian population.
J Cyst Fibros. 2008 Jan;7(1):54-9. Epub 2007 Jun 14., [PMID:17572159]

Abstract [show]
The nature and frequency of the major CFTR mutations in the North African population remain unclear, although a small number of CFTR mutation detection studies have been done in Algeria and Tunisia, showing largely European mutations such as F508del, G542X and N1303K, albeit at different frequencies, which presumably emerged via population admixture with Caucasians. Some unique mutations were identified in these populations. This is the first study that includes a genetic and clinical evaluation of CF patients living in Algeria. In order to offer an effective diagnostic service and to make accurate risk estimates, we decided to identify the CFTR mutations in 81 Algerian patients. We carried out D-HPLC, chemical-clamp denaturing gradient gel electrophoresis, multiplex amplification analysis of the CFTR gene and automated direct DNA sequencing. We identified 15 different mutations which account for 58.5% of the CF chromosomes. We used a quantitative PCR technique (quantitative multiplex PCR short fragment fluorescence analysis) to screen for deletion/duplication in the 27 exons of the gene. Taking advantage of the homogeneity of the sample, we report clinical features of homozygous CF patients. As CFTR mutations have been detected in males with infertility, 46 unrelated Algerian individuals with obstructive azoospermia were also investigated.

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59 Moreover, we have identified two complex mutations: R74W-D1270N in the mother of an Algerian F508del heterozygous CF patient, and none of these variations were inherited by the child. Login to comment
60 Using intragenic polymorphisms, we have confirmed that R74W and D1270N were not inherited by the F508del heterozygous CF child. Login to comment
90 Table 1 CFTR mutations detected in 36 Algerian patients (N=72 CF chromosomes) Mutations Substitution nucleotide Substitution amino acid Localisation N % Cum. fr. hF508del del CTT Del phe 507/508 Exon 10 12 16.7 16.7 N1303K C→G 4041 Asn→Lys 1303 Exon 21 6 8.3 25.0 711+1G→T G→T711+1 MRNA splicing defect Intron 5 6 8.3 33.3 2183AA/G del A2184 Frameshift Exon 13 3 4.2 37.5 A→G 2183 1609delCA delCA Frameshift Exon 10 2 2.8 40.3 1812-1G→A G→A 1812-1 mRNA splicing defect Intron 11 2 2.8 43.1 V562I G→A 1816 Val→Ile 562 Exon 12 2 2.8 45.9 V754M G→A 2392 Val→Met 754 Exon 13 1 1.4 47.3 W1282X G→A 3978 Trp→Stop 1282 Exon 20 3 4.2 51.5 621+3A/Ga A→G 621+3 mRNA splicing defect Intron 4 1 1.4 52.9 4332delTGa delTG4332 Frameshift Exon 23 G542X G→T 1756 Gly→Stop 542 Exon 11 1 1.4 54.3 4271delC del A 4271 Frameshift Exon 23 1 1.4 55.7 S977F C→T 3062 Ser→Phe 97 Exon 16 1 1.4 57.1 21Kb del 21-kb del Del AA E2-E3 1 1.4 58.5 R74W C→T 352 Arg→Trp 74 Exon 3 0 0 D1270N G→A 3940 Asp→Asn 1270 Exon 20 0 0 Total 43 58.5 N=number of chromosomes; Cum. fr.=cumulative frequency. Login to comment

[hide] Diagnostic testing by CFTR gene mutation analysis ... J Mol Diagn. 2005 May;7(2):289-99. Schrijver I, Ramalingam S, Sankaran R, Swanson S, Dunlop CL, Keiles S, Moss RB, Oehlert J, Gardner P, Wassman ER, Kammesheidt A
Diagnostic testing by CFTR gene mutation analysis in a large group of Hispanics: novel mutations and assessment of a population-specific mutation spectrum.
J Mol Diagn. 2005 May;7(2):289-99., [PMID:15858154]

Abstract [show]
Characterization of CFTR mutations in the U.S. Hispanic population is vital to early diagnosis, genetic counseling, patient-specific treatment, and the understanding of cystic fibrosis (CF) pathogenesis. The mutation spectrum in Hispanics, however, remains poorly defined. A group of 257 self-identified Hispanics with clinical manifestations consistent with CF were studied by temporal temperature gradient electrophoresis and/or DNA sequencing. A total of 183 mutations were identified, including 14 different amino acid-changing novel variants. A significant proportion (78/85) of the different mutations identified would not have been detected by the ACMG/ACOG-recommended 25-mutation screening panel. Over one third of the mutations (27/85) occurred with a relative frequency >1%, which illustrates that the identified mutations are not all rare. This is supported by a comparison with other large CFTR studies. These results underscore the disparity in mutation identification between Caucasians and Hispanics and show utility for comprehensive diagnostic CFTR mutation analysis in this population.

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103 Table 1. Continued Mutations in 257 patients Allele counts of each mutation % of variant alleles (183) % of all alleles tested (514) R1070W 1 0.55 0.19 R1158X 1 0.55 0.19 R1438W 1 0.55 0.19 R334W 2 1.09 0.39 R352W 1 0.55 0.19 R553X 2 1.09 0.39 R668C 2 1.09 0.39 R74W 3 1.64 0.58 R75X 3 1.64 0.58 S1235R 2 1.09 0.39 S492F 2 1.09 0.39 S549N 1 0.55 0.19 S573CS573C 1 0.55 0.19 S945L 1 0.55 0.19 T351S 1 0.55 0.19 T501A 2 1.09 0.39 T604ST604S 1 0.55 0.19 V11I 1 0.55 0.19 V201 mol/L 1 0.55 0.19 V232D 2 1.09 0.39 V754 mol/L 1 0.55 0.19 W1089X 2 1.09 0.39 W1098C 1 0.55 0.19 W1204X 4 2.19 0.78 Y563N 1 0.55 0.19 Y913XY913X 1 0.55 0.19 85 different mutations 183 100.00 35.60 Novel variants are in boldface, mutations on the ACMG/ACOG panel are italicized. Login to comment
187 CFTR Sequence Variants Identified in Five Comprehensive CFTR Studies in US Hispanics CFTR mutations Alleles Relative mutation frequency (%) (of 317) deltaF508 123 38.80 3876delA 15 4.70 G542X 12 3.80 406 - 1GϾA 8 2.50 3849 ϩ 10kbCϾT 5 1.60 R75X 4 1.30 935delA 4 1.30 S549N 4 1.30 W1204X 4 1.30 R334W 4 1.30 2055del9ϾA 3 1 R74W 3 1 H199Y 3 1 L206W 3 1 663delT 3 1 3120 ϩ 1GϾA 3 1 L997F 3 1 I1027T 3 1 R1066C 3 1 W1089X 3 1 D1270N 3 1 2105del13insAGAAA 3 1 Q98R 2 Ͻ1 E116K 2 Ͻ1 I148T 2 Ͻ1 R668C 2 Ͻ1 P205S 2 Ͻ1 V232D 2 Ͻ1 S492F 2 Ͻ1 T501A 2 Ͻ1 1949del84 2 Ͻ1 Q890X 2 Ͻ1 3271delGG 2 Ͻ1 3272 - 26AϾG 2 Ͻ1 G1244E 2 Ͻ1 D1445N 2 Ͻ1 R553X 2 Ͻ1 E588V 2 Ͻ1 1717 - 8GϾA 2 Ͻ1 A1009T 2 Ͻ1 S1235R 2 Ͻ1 G85E 1 Ͻ1 296 ϩ 28AϾG 1 Ͻ1 406 - 6TϾC 1 Ͻ1 V11I 1 Ͻ1 Q179K 1 Ͻ1 V201 mol/L 1 Ͻ1 874insTACA 1 Ͻ1 I285F 1 Ͻ1 deltaF311 1 Ͻ1 F311L 1 Ͻ1 L320V 1 Ͻ1 T351S 1 Ͻ1 R352W 1 Ͻ1 1248 ϩ 1GϾA 1 Ͻ1 1249 - 29delAT 1 Ͻ1 1288insTA 1 Ͻ1 1341 ϩ 80GϾA 1 Ͻ1 1429del7 1 Ͻ1 1525 - 42GϾA 1 Ͻ1 P439S 1 Ͻ1 1717 - 1GϾA 1 Ͻ1 1811 ϩ 1GϾA 1 Ͻ1 deltaI507 1 Ͻ1 G551D 1 Ͻ1 A559T 1 Ͻ1 Y563N 1 Ͻ1 (Table continues) In this study, we used temporal temperature gradient gel electrophoresis (TTGE) and direct DNA sequencing to increase the sensitivity of mutation detection in U.S. Hispanics, and to determine whether additional mutations are recurrent. Login to comment
201 Comparison of Relative Frequencies of CFTR Sequence Variants in Comprehensive CFTR Studies in US and Mexican Hispanics This study % Orozco 2000 % US/ Mexican % deltaF508 28.96 54.48 43.72 G542X 3.83 8.28 5.19 406 - 1GϾA 3.28 2.07 2.38 W1204X 2.19 Ͻ1 1.08 R74W 1.64 Ͻ1 R75X 1.64 2.07 1.51 H199Y 1.64 Ͻ1 Ͻ1 L206W 1.64 Ͻ1 L997F 1.64 Ͻ1 I1027T 1.64 Ͻ1 2055del9ϾA 1.64 1.38 1.27 D1270N 1.64 Ͻ1 E116K 1.09 Ͻ1 V232D 1.09 Ͻ1 R334W 1.09 Ͻ1 S492F 1.09 Ͻ1 T501A 1.09 Ͻ1 R553X 1.09 Ͻ1 Ͻ1 E588V 1.09 Ͻ1 R668C 1.09 Ͻ1 Q890X 1.09 Ͻ1 W1089X 1.09 Ͻ1 S1235R 1.09 Ͻ1 D1445N 1.09 Ͻ1 3876delA 1.09 3.24 1717 - 8GϾA 1.09 Ͻ1 3272 - 26AϾG 1.09 Ͻ1 A1009T 1.09 Ͻ1 deltaI507 Ͻ1 3.45 1.30 S549N Ͻ1 3.45 1.95 G567A Ͻ1 Ͻ1 I148T 2.07 1.08 I506T 1.38 Ͻ1 N1303K 2.76 1.08 935delA 1.38 1.30 2183AAϾG 1.38 Ͻ1 3199del6 1.38 Ͻ1 3849 ϩ 10kbCϾT Ͻ1 1.30 ACMG/ACOG italicized. Login to comment

[hide] High frequency of the R75Q CFTR variation in patie... J Cyst Fibros. 2004 Aug;3(3):189-91. Divac A, Nikolic A, Mitic-Milikic M, Nagorni-Obradovic L, Petrovic-Stanojevic N, Dopudja-Pantic V, Nadaskic R, Savic A, Radojkovic D
High frequency of the R75Q CFTR variation in patients with chronic obstructive pulmonary disease.
J Cyst Fibros. 2004 Aug;3(3):189-91., [PMID:15463907]

Abstract [show]
We performed the complete screening of the CFTR gene in a group of 31 patients with COPD in order to investigate the impact of mutations and polymorphisms in the CFTR gene. The cumulative frequency of CFTR mutations (17.74%) was significantly higher than in our general population (P < 0.0001). The R75Q was significantly overrepresented in COPD patients (8.06%; P = 0.002). In all patients carrying the R75Q chronic bronchitis was a dominant symptom of COPD, and all were homozygous for the V470 allele. These findings suggest that R75Q mutation could be characteristic CFTR variant for COPD patients.

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39 Six different mutations (R75Q, F508del, G126D, L997F, F1052V, R74W) were identified on 11 (17.74%) of the 62 chromosomes, giving a significantly higher frequency than in our general population ( P < 0.0001, 95%CI: 2.60-36.21). Login to comment
59 Table 1 CFTR genotypes in COPD patients No. of cases CFTR gene mutation IVS8 Tn M470V genotype 1 R75Q/R75Q 7/7 V470/V470 1 L997F/R75Q 7/9 V470/V470 2 R75Q/- 7/7 V470/V470 1 F508del/- 7/9 M470/V470 1 F508del/- 5/9 M470/M470 1 G126D/- 7/9 M470/M470 1 F1052V/- 7/7 M470/V470 1 R74W/- 7/7 M470/M470 2 -/- 5/7 V470/V470 3 -/- 5/7 M470/V470 1 -/- 5/7 M470/M470 1 -/- 5/9 M470/V470 3 -/- 7/9 M470/V470 6 -/- 7/7 V470/V470 4 -/- 7/7 M470/V470 -/- 7/7 M470/M470 A. Divac et al. / Journal of Cystic Fibrosis 3 (2004) 189-191190 Acknowledgements This work was supported by grant 1417 from Ministry for Science, Technologies and Development of Serbia. Login to comment

[hide] Cystic fibrosis transmembrane conductance regulato... J Hepatol. 2002 Aug;37(2):192-7. Girodon E, Sternberg D, Chazouilleres O, Cazeneuve C, Huot D, Calmus Y, Poupon R, Goossens M, Housset C
Cystic fibrosis transmembrane conductance regulator (CFTR) gene defects in patients with primary sclerosing cholangitis.
J Hepatol. 2002 Aug;37(2):192-7., [PMID:12127423]

Abstract [show]
BACKGROUND/AIMS: Because biliary tract lesions that resemble those of primary sclerosing cholangitis (PSC) may occur in cystic fibrosis (CF), we examined the prevalence and influence of CF transmembrane conductance regulator (CFTR) gene mutations in PSC patients. METHODS: Genomic DNA was analyzed in 29 consecutive PSC patients and in 115 healthy control individuals. A scanning method followed by direct DNA sequencing was used to scan the CFTR coding regions. RESULTS: Four patients (13.8%) were heterozygous for a CFTR mutation, including a new putative severe CF-causing mutation (N782K), and three mild defects (L997F, D1270N, and S1235R). The comparison of PSC patients with healthy controls showed no significant difference in the frequency of CFTR mutations (P=0.415). In addition, two patients (6.9%) were heterozygous for the IVS8-5T allele, which is not significantly different from the 5-6%-prevalence in the general population. Unusual clinical features including a severe outcome in childhood, with a lethal outcome at age 22, and biliary aspergillosis were recorded in patients with a CFTR mutation. CONCLUSIONS: The proportion of CF carriers is not significantly higher in PSC patients than in the general population. The possibility that CFTR mutations may contribute to a severe clinical course in PSC patients is worth further examining.

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78 Four additional subjects (3.5%) carried one of the following mild defects: R117H, R347H, R74W-D1270N and R668C-G576A. Login to comment

[hide] Spectrum of CFTR mutations in cystic fibrosis and ... Hum Mutat. 2000;16(2):143-56. Claustres M, Guittard C, Bozon D, Chevalier F, Verlingue C, Ferec C, Girodon E, Cazeneuve C, Bienvenu T, Lalau G, Dumur V, Feldmann D, Bieth E, Blayau M, Clavel C, Creveaux I, Malinge MC, Monnier N, Malzac P, Mittre H, Chomel JC, Bonnefont JP, Iron A, Chery M, Georges MD
Spectrum of CFTR mutations in cystic fibrosis and in congenital absence of the vas deferens in France.
Hum Mutat. 2000;16(2):143-56., [PMID:10923036]

Abstract [show]
We have collated the results of cystic fibrosis (CF) mutation analysis conducted in 19 laboratories in France. We have analyzed 7, 420 CF alleles, demonstrating a total of 310 different mutations including 24 not reported previously, accounting for 93.56% of CF genes. The most common were F508del (67.18%; range 61-80), G542X (2.86%; range 1-6.7%), N1303K (2.10%; range 0.75-4.6%), and 1717-1G>A (1.31%; range 0-2.8%). Only 11 mutations had relative frequencies >0. 4%, 140 mutations were found on a small number of CF alleles (from 29 to two), and 154 were unique. These data show a clear geographical and/or ethnic variation in the distribution of the most common CF mutations. This spectrum of CF mutations, the largest ever reported in one country, has generated 481 different genotypes. We also investigated a cohort of 800 French men with congenital bilateral absence of the vas deferens (CBAVD) and identified a total of 137 different CFTR mutations. Screening for the most common CF defects in addition to assessment for IVS8-5T allowed us to detect two mutations in 47.63% and one in 24.63% of CBAVD patients. In a subset of 327 CBAVD men who were more extensively investigated through the scanning of coding/flanking sequences, 516 of 654 (78. 90%) alleles were identified, with 15.90% and 70.95% of patients carrying one or two mutations, respectively, and only 13.15% without any detectable CFTR abnormality. The distribution of genotypes, classified according to the expected effect of their mutations on CFTR protein, clearly differed between both populations. CF patients had two severe mutations (87.77%) or one severe and one mild/variable mutation (11.33%), whereas CBAVD men had either a severe and a mild/variable (87.89%) or two mild/variable (11.57%) mutations.

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215 Mutations D1270N and R74W have been independently reported elsewhere to be CF alleles [Anguiano et al., 1992; Claustres et al., 1993]. Login to comment

[hide] Screening practices for mutations in the CFTR gene... Hum Mutat. 2000;15(2):135-49. Girodon-Boulandet E, Cazeneuve C, Goossens M
Screening practices for mutations in the CFTR gene ABCC7.
Hum Mutat. 2000;15(2):135-49., [PMID:10649490]

Abstract [show]
Cystic fibrosis transmembrane conductance regulator (CFTR) gene studies are now one of the most frequent activities in clinical molecular genetics laboratories. The number of requests is growing, owing to the increasingly wide range of recognized CFTR gene diseases (cystic fibrosis, congenital bilateral absence of the vas deferens, disseminated bronchiectasis, allergic bronchopulmonary aspergillosis and chronic pancreatitis), and the availability of efficient molecular tools for detecting mutations. A growing number of tests capable of simultaneously detecting several frequent CF mutations are being developed, and commercial kits are now available. The most recent kits detect nearly 90% of defective alleles in Caucasians, a rate high enough for carrier screening and for the majority of diagnostic requests. However, because of the wide variety of molecular defects documented in the CFTR gene, only a limited number of laboratories have mastered the entire panoply of necessary techniques, while other laboratories have to refer certain cases to specialized centers with complementary and/or scanning tools at their disposal. A good knowledge of CFTR diseases and their molecular mechanisms, together with expertise in the various techniques, is crucial for interpreting the results. Diagnostic strategies must take into account the indication, the patient's ethnic origin, and the time available in the framework of genetic counseling. This review presents the methods most frequently used for detecting CFTR gene mutations, and discusses the strategies most suited to the different clinical settings.

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179 The functional consequence of the double mutant R74W-D1270N was recently studied [Fanen et al., 1999]: R74W was shown to be a polymorphism with regard to chloride channel function, but was found to aggravate the deleterious effect of D1270N. Login to comment
180 D1270N alone is thus considered as a CBAVD mutation, while R74W-D1270N is considered as a CF mutation, in keeping with a previous clinical observation [Casals et al., 1995]. Login to comment

[hide] Structure-function analysis of a double-mutant cys... FEBS Lett. 1999 Jun 11;452(3):371-4. Fanen P, Clain J, Labarthe R, Hulin P, Girodon E, Pagesy P, Goossens M, Edelman A
Structure-function analysis of a double-mutant cystic fibrosis transmembrane conductance regulator protein occurring in disorders related to cystic fibrosis.
FEBS Lett. 1999 Jun 11;452(3):371-4., [PMID:10386624]

Abstract [show]
A number of disorders related to cystic fibrosis have been described since the cloning of the cystic fibrosis gene, including infertility due to the congenital bilateral absence of the vas deferens. We have identified, in several patients, complex cystic fibrosis transmembrane conductance regulator genotypes like double-mutant alleles. We have now analyzed the structure-function relationships of one of these mutants, R74W-D1270N cystic fibrosis transmembrane conductance regulator, expressed in HeLa cells, to evaluate the contribution of each mutation in the phenotype. We found that R74W cystic fibrosis transmembrane conductance regulator appears to be a polymorphism, while D1270N cystic fibrosis transmembrane conductance regulator could be responsible for the congenital bilateral absence of the vas deferens phenotype. The combination of the two produced a more severe effect on the chloride conductance pathway as well as on the phenotype.

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13 We have now investigated the structure-function relationships of one of these mutants, R74W-D1270N-CFTR, using a heterologous expression system. Login to comment
14 The 'rst mutation lies in the intracellular N-terminus of the CFTR protein and the second within the second nucleotide binding domain (NBD2), replacing an arginine by a tryptophan at position 74 and an aspartic acid by an asparagine at position 1270 [9,10]. Login to comment
20 These assays showed that the R74W mutation should be considered to be a polymorphism and suggest that D1270N alone is su¤cient to produce the CBAVD phenotype, while the combination of the two increases the chloride conductance pathway dysfunction and the phenotype. Login to comment
87 The majority (67%) of the R74W-CFTR cells showed an increased rate of change in MEQ £uorescence when exposed to the stimulatory cocktail, indicating activation of a cAMP-dependent anion pathway, 45% of these cells were fast responders. Login to comment
88 Lastly, 89% of D1270N-CFTR and 81% of R74W-D1270N-CFTR also had a cAMP-responsive anion conductance with di¡erent ratios between fast and slow responding cells (38% fast in D1270N-CFTR and 24% fast in R74W-D1270-CFTR). Login to comment
90 Discussion We have analyzed the structure-function relationships of three CFTR mutations, R74W, D1270N and the R74W-D1270N double-mutant, and compared their properties with those of wild-type CFTR. Login to comment
91 R74W was 'rst described in isolation [10], but has since been found in association with D1270N (Mireille Claustres, personal communication). Login to comment
93 Finally, the R74W-D1270N double-mutant was 'rst identi'ed in a compound, vF508, heterozygote with clinical features of CBAVD, rhinitis, recurrent respiratory infections and elevated sweat chloride concentrations [13]. Login to comment
97 To our knowledge, this is the 'rst reported expression of the R74W- and/or D1270N-CFTR mutant and the 'rst functional description of a double-mutant associated with CBAVD, a disorder related to CF. Login to comment
104 HeLa cells were transfected with either wild-type CFTR (vFstim/vFbasal = 12), R74W-CFTR (vFstim/vFbasal = 11), D1270N-CFTR (vFstim/vFbasal = 3) or R74W-D1270N-CFTR (vFstim/ vFbasal = 2). Login to comment
105 Table 1 Summary of the MEQ assay results Cell type Wild-type R74W D1270N R74W-D1270N PTracer Total 53 30 27 26 28 Non-responding 8 10 3 5 28 All responding 45 (85%)a 20 (67%)a 24 (89%)a 21 (81%)a 0 Fast 21 (47%)b 9 (45%)b 9 (38%)b 5 (24%)b 0 vFstim/vFbasal 13.3 þ 6.3c 11.9 þ 8.7c 7.7 þ 2.4c 7.3 þ 2.7c Range 5.4^26.3 5.9^34 5.6^12.8 5.2^12 Slow 24 (53%)b 11 (55%)b 15 (62%)b 16 (76%)b 0 vFstim/vFbasal 2.7 þ 1.1c 2.5 þ 0.9c 2.8 þ 0.9c 3.2 þ 1.2c Range 1.3^5 1.1^4.1 1.4^4.5 1.2^4.9 a Percentage of all cells. Login to comment
107 c Mean values þ S.D. FEBS 22106 -6-99 P. Fanen et al./FEBS Letters 452 (1999) 371^374 373 Expression of these three mutant genes in HeLa cells showed that R74W-CFTR, D1270N-CFTR and R74W-D1270N-CFTR proteins elicited cAMP-dependent chloride £uxes. Login to comment
108 R74W-CFTR elicited a cAMP-responsive anion conductance at the same rate as wild-type CFTR. Login to comment
110 On the basis of the results of the functional assay, we postulate that the R74W mutation is a sequence variation that has no deleterious e¡ect alone. Login to comment
111 D1270N and R74W-D1270N had abnormal responsive patterns. Login to comment
118 The R74W-D1270N double-mutant was associated with a 7T background in the three patients studied. Login to comment
122 We therefore believe that the R74W-D1270N double-mutant is responsible for the CBAVD phenotype. Login to comment
123 The contribution of each mutant to this phenotype may be as follows: R74W is a polymorphism which may slightly reduce the normal amount of CFTR protein (67% of responding cells versus 81^89%) in vivo and D1270N has a cAMP-responsive anion conductance with di¡erent ratios between fast and slow responder cells, as for the R117H mutation. Login to comment
124 We infer that the combination of R74W enhances the e¡ect of D1270N by reducing the number of fast responder cells, as a consequence of the defective regulation of the R74W-D1270N mutated protein or of a di¡erent turn-over of the protein at the cell surface in vivo. Login to comment
125 This is supported by the fact that the compound heterozygote vF508/ D1270N described by Anguiano et al. occurred in a CBAVD patient with normal sweat sodium and chloride values, i.e. normal chloride secretion [9], whereas the compound heterozygote vF508/R74W-D1270N described by Casals et al. had a more severe phenotype and elevated sweat chloride concentrations suggesting an abnormal chloride secretion [13]. Login to comment

[hide] Missense mutations in the cystic fibrosis gene in ... Hum Mutat. 1999;14(6):510-9. Lazaro C, de Cid R, Sunyer J, Soriano J, Gimenez J, Alvarez M, Casals T, Anto JM, Estivill X
Missense mutations in the cystic fibrosis gene in adult patients with asthma.
Hum Mutat. 1999;14(6):510-9., [PMID:10571949]

Abstract [show]
Asthma is a complex genetic disorder that affects 5% of adults and 10% of children worldwide. The complete characterization of the cystic fibrosis transmembrane conductance regulator (CFTR) gene identified missense mutations in 15% of 144 unrelated adult patients with asthma, but in none of 41 subjects from the general population. The four more common mutations were analyzed in an extended sample consisting of 184 individuals from the general population and did not show a significant difference in frequency. The hyperfunctional CFTR M470 allele was detected in 90% of patients with CFTR missense mutations, but in 63% of subjects from the general population and 63% of asthma patients without CFTR mutations. None of the patients with missense mutations had the 5T allele of intron 8 of CFTR, responsible for low CFTR levels, while it was detected in 8% of asthma patients without CFTR mutations and in 9% of subjects from the general population. These findings suggest a putative role for a combination of CFTR missense mutations, including the M470 allele, in the genetic variability of asthma.

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84 Characteristics of Asthmatic Patients With CFTR Mutations CFTR Age IgE Skin Patients genotype1 M470V2 PolyT3 Sex Years BHR4 IU/ml5 test6 SB221 R74W,V8551 M/V 7/7 M 67 - 329 + SB36 R75Q / - M/V 7/7 F 61 + 59 + SB47 R75Q / - M/V 7/9 M 67 NA 42 NA SB131 R75Q / - M/V 7/7 F 69 + 41 - SB296 R75Q / - M/V 7/9 F 45 + 96 - SB251 I148T / - M/V 7/9 F 70 - 25 - SB212 A534Q / - M/M 7/7 F 46 + 69 + SB125 R668C,G576A N/V 7/7 M 62 + 21 - SB154 R668C,G576A M/V 7/7 M 65 + 93 + SB231 R668C,G576A M/V 7/7 F 45 + 158 + SB112 R668C / - M/V 7/7 M 64 + 1350 + SB304 R668C,T582R M/V 7/7 F 78 - 7 - SB56 T896I / - M/V 7/7 M 72 + 77 - SB117 L997F / - V/V 7/9 F 81 NA 6 NA SB143 L997F/L997F V/V 7/7 F 39 NA 129 NA SB173 L997F / - M/V 7/9 F 67 + 127 - SB148 M1028R / - M/V 7/7 F 48 + 23 - SB32 R1066C / - M/V 7/7 F 69 - 9 - SB69 T1142I / - M/M 7/9 M 65 - 158 + SB92 R116L / - M/V 7/7 M 78 NA 64 NA SB53 T1220I / - M/M 7/9 F 60 + 62 + SB40 ∆F508 / - M/M 79 F 62 + 34 + SB9 - / - M/M 5/9 F 61 - 169 - SB20 - / - M/V 5/5 F 57 - 245 + SB116 - / - V/V 5/7 F 33 NA 41 NA SB118 - / - M/V 5/9 M 83 + 63 - SB140 - / - V/V 5/7 F 72 NA 35 NA SB142 - / - M/V 5/7 F 59 + 108 + SB201 - / - M/V 5/7 M 27 - 297 + SB205 - / - M/V 5/7 F 56 - 20 - SB284 - / - M/V 5/7 F 71 - 40 NA SB316 - / - M/V 5/7 F 78 NA 20 - 1 The CFTR genotype was studied by DGGE/SSCP analysis of all CFTR exons and intronic flanking sequences. Login to comment
93 Characteristics of 15 Amino Acid Variants/Mutants in the CFTR Gene Detected in 21 Patients With Asthma Other Evolutive Conservative Other mutations Mutation1 Reference2 Exon Domain3 Patients4 phenotypes5 conservation6 change7 at same position R74W Claustres et al., 1993 3 IC1 1 CF-PS/CBAVD b, m, r, s NC - R75Q Zielenski et al., 1991 3 IC2 4 CF-PS/DB/CBAVD/ b, d, m, r, s, x NC R75X (CF) CF Parents R75L (CBAVD) I148T Bozon et al., 1994 4 IC2 1 CF-PS b, d, m, r, s, x NC I148N (CF) A534Q This report 11 NBF1 1 - b, m NC A534E (CF) G576A Fanen et al., 1992 12 NBF1 3 CF-PS/CBAVD b, m, r, s NC G576X (CF) T582R Casals et al., 1997 12 NBF1 1 CF-PS b, d, m, r, s, x NC T582I (CF) R668C Fanen et al., 1992 13 R 5 DB/CF-PS/CBAVD/ b, d, m, r, s, x NC - CF Parents V855I This report 14a IC6 1 - b, r, s C - T896I This report 15 EC4 1 - b, d, m, r, s NC - L997F Fanen et al., 1992 17a TM9 3 DB/CF-PS/CBAVD/ b, d, m, r, s, x C - non-CF M1028R This report 17a TM10 1 - d NC M1028I (CF) T2066C Fanen et al., 1992 17b IC8 1 DB/CF-PI b, d, m, r, s, x NC R1066S (CF) R1066L (CF) R1066H (CF/CBAVD) T1142I This report 18 TM12 1 - b, d, m, r, s, x NC - R1162L Fanen et al., 1992 19 IC9 1 non-CF b, d, m, r, s, x NC R1162X (CF) T1220I Ghanem et al., 1994 19 NBF2 1 DB/non-CF b, d NC - 1 Mutation name according to the Cystic Fibrosis Genetic Analysis Consortium. Login to comment

[hide] SSCP analysis: a blind sensitivity trial. Hum Mutat. 1997;10(1):65-70. Jordanova A, Kalaydjieva L, Savov A, Claustres M, Schwarz M, Estivill X, Angelicheva D, Haworth A, Casals T, Kremensky I
SSCP analysis: a blind sensitivity trial.
Hum Mutat. 1997;10(1):65-70., [PMID:9222762]

Abstract [show]
Studies of the sensitivity of SSCP analysis usually have been performed under conditions contrary to the rules of quality control trials and have produced widely different results. We have performed a blind trial of the sensitivity of SSCP analysis for the detection of mutations in fragments up to 500 bp in length under a fixed single set of electrophoretic conditions. The mutation detection rate was 84%. In addition, we have identified a second mutation in nine samples. All these mutations are polymorphisms, including a novel polymorphism 1248 + 52T/C first reported in the present work.

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22 List of Mutations Included in the Experiment and Original Method of Detection Used by the Referring Laboratory Referring Probe Original method laboratory no.a Mutation Exon of detection Original SSCP conditions Institut de 1 1677delTA 10 Heteroduplexes Recerca 1 1859G/C 12 DDGE Oncologica, 3 W1282X 20 SSCPb 6% 19:1 (AA:bisAA) 4°C 5h 30W Department 4 delF508 10 Heteroduplexes de Genetica 4 Q1313X 20 SSCPb 6% 19:1 (AA:bisAA) 4°C 5h 30W Molecular, 5 1609delCA 10 SSCPb 6% 19:1 (AA:bisAA) RT 28h 10W10% glycerol Barcelona, 7 T582R 12 DGGE Spain 8 1898+3G→A ivs 12 DGGE Molecular 910085 1161delC 7 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Genetics 860176 1138insG 7 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Laboratory, 930215 1154insTC 7 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Royal 930838 delF508 10 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Manchester 930127 delI507 10 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Children`s 931205 Q493X 10 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm Hospital, 900592 V520F 10 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm UK G12984 S489X 10 SSCP/Heteroduplexes 9% 49:1 (AA:bisAA) 4°C 20 h 10V/cm 910143 G551D 11 ARMS 930274 S549N 11 SSCP/Heteroduplexes 10% 49:1 (AA:bisAA) 4°C 20 h 10V/cm 920132 1811+1G→C ivs 11 SSCP/Heteroduplexes 10% 49:1 (AA:bisAA) 4°C 20 h 10V/cm 930140 1898+1G→A ivs 12 SSCP/Heteroduplexes 930334 W1282X 20 SSCP/Heteroduplexes 7.25% 49:1 (AA:bisAA) 4°C 20 h 10V/cm 140735 3850-1G→A 20 SSCP/Heteroduplexes 7.25% 49:1 (AA:bisAA) 4°C 20 h 10 V/cm Laboratoire 293 G551D 11 SSCPb 5% 19:1 (AA:bisAA) 4°C 5 h 50W and de Biochimie 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol Genetique, 324 S549R 11 ASO Hybridization Centre 649 1898+1G→A ivs 12 DGGE Hospitalier 583 E585X 12 DGGE Universitaire 710 L967S 15 DGGE Montpellier, 325 S945L 15 SSCPb 5% 19:1 (AA:bisAA) 4° 5h 50W and France 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 473 N1303H 21 SSCPb 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 216 300delA 3 SSCP 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 287 394delTT 3 SSCP 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 559 R74W 3 SSCP 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 237 P67L 3 DGGE 1023 R75X 3 DGGE 885 1215delG 7 DGGE 113 Y122X 4 DGGE, SSCP 356 621+1G→T ivs 4 SSCP 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 709 621+2T→G ivs 4 SSCP 5% 19:1 (AA:bisAA)4°C 5h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol 802 I148T 4 DGGE 1016 Q98R 4 DGGE V75 R117H 4 SSCP 5% 19:1 (AA:bisAA) 4°C 5 h 50W and 5% 19:1 (AA:bisAA) RT 18h 8W 10%glycerol a Identification numbers given by referring laboratories. Login to comment
57 Type of Mutations Detected by SSCP Analysis in This Study Type of mutation Mutation Mutation characteristics Detected by SSCP analysis Deletions 1677delTA deletion of TA from 1677 Yes delF508 deletion of 3 bp from 1655 Yes delI507 deletion of 3 bp from 1648 Yes 1609delCA deletion of CA from 1609 Yes 1161delC deletion of C at 1161 Yes 300delA deletion of A at 300 Yes 394delTT deletion of TT from 394 Yes 1215delG deletion of G at 1215 No Insertions 1138insG insertion of G after 1138 Yes 1154insTC insertion of TC after 1154 Yes Base 1859G/C Yes substitutions W1282X G→A at 3978 Yes Q1313X C→T at 4069 Yes T582R C→G at 1877 Yes 1898+3G→A A→G at 1898+3 Yes Q493X C→T at 1609 Yes V520F G→T at 1690 Yes S489X C→A at 1598 Yes G551D G→A at 1784 No S549N G→A at 1778 Yes 1811+1G→C G→C at 1811+1 Yese 1898+1G→A G→A at 1898 Yes 3850-1G→A G→A at 3850-1 Yes S549R T→G at 1779 Yes E585X G→T at 1885 Yes L967S C→T at 2966 Yes S945L C→T at 2966 No N1303H A→C at 4039 Yes R74W C→T at 352 Yes P67L C→T at 332 Yes R75X C→T at 355 Yes Y122X T→A at 498 No 621+1G→T G→T at 621+1 No 621+2T→G T→G at 621+2 No I148T T→C at 575 Yes Q98R A→G at 425 Yes R117H G→A at 482 Yes FIGURE 1. Login to comment

[hide] Complex cystic fibrosis allele R334W-R1158X result... Hum Mutat. 1996;8(2):134-9. Duarte A, Amaral M, Barreto C, Pacheco P, Lavinha J
Complex cystic fibrosis allele R334W-R1158X results in reduced levels of correctly processed mRNA in a pancreatic sufficient patient.
Hum Mutat. 1996;8(2):134-9., [PMID:8844211]

Abstract [show]
CFTR alleles containing two mutations have been very rarely found in cystic fibrosis (CF) patients. They provide an opportunity to study the effect of two in cis-interacting gene defects on gene expression. Here, we describe a three-generation CF family with a complex CFTR allele that has not been previously described, containing the missense mutation R334W in exon 7 and the nonsense mutation R1158X in exon 19. Lymphocyte RNA analysis showed that (1) the mRNA corresponding to the complex allele is present although at markedly reduced levels; and (2) the nonsense mutation does not lead to detectable skipping of exon 19. The clinical picture of the patients with the genotype R334W-R1158X/delta F508 is characterized by pancreatic sufficiency and an atypical course of the disease.

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38 Other in cis missense mutations have been reported, namely F508C-Sl251N (Kalin et al., 1992), G628R- S1235R (Mercier et al., 1995) and R74W- D1270N (Verlingue et al., 1993). Login to comment

[hide] Extensive analysis of 40 infertile patients with c... Hum Genet. 1995 Feb;95(2):205-11. Casals T, Bassas L, Ruiz-Romero J, Chillon M, Gimenez J, Ramos MD, Tapia G, Narvaez H, Nunes V, Estivill X
Extensive analysis of 40 infertile patients with congenital absence of the vas deferens: in 50% of cases only one CFTR allele could be detected.
Hum Genet. 1995 Feb;95(2):205-11., [PMID:7532150]

Abstract [show]
Mutations in the cystic fibrosis (CF) conductance transmembrane regulator (CFTR) gene have been detected in patients with CF and in males with infertility attributable to congenital bilateral absence of the vas deferens (CBAVD). Thirty individuals with CBAVD and 10 with congenital unilateral absence of the vas deferens (CUAVD) were analyzed by single-strand conformation analysis and denaturing gradient gel electrophoresis for mutations in most of the CFTR gene. All 40 individuals were pancreatic sufficient, but twenty patients had recurrent or sporadic respiratory infections, asthma/asthmatic bronchitis, and/or rhino-sinusitis. Agenesia or displasia of one or both seminal vesicles was detected in 30 men and other urogenital malformations were present in six subjects. Among the 40 samples, we identified 13 different CFTR mutations, two of which were previously unknown. One new mutation in exon 4 was the deletion of glutamic acid at codon 115 (delta E115). A second new mutation was found in exon 17b, viz., an A --> C substitution at position 3311, changing lysine to threonine at codon 1060 (K1060T). CFTR mutations were detected in 22 out of 30 (73.3%) CBAVD patients and in one out of 10 (10%) CUAVD individuals, showing a significantly lower incidence of CFTR mutations in CBAVD/CUAVD patients (P << 0.0001), compared with that found in the CF patient population. Only three CBAVD patients were found with more than one CFTR mutation (delta F508/L206W, delta F508/R74W + D1270N, R117H/712-1G --> T), highlighting L206W, R74W/D1270N, and R117H as benign CF mutations. Sweat electrolyte values were increased in 76.6% of CBAVD patients, but three individuals without CFTR mutations had normal sweat electrolyte levels (10% of the total CBAVD patients), suggesting that factors other than CFTR mutations are involved in CBAVD. The failure to identify a second mutation in exons and their flanking regions of the CFTR gene suggests that these mutations could be located in introns or in the promoter region of CFTR. Such mutations could result in CFTR levels below the minimum 6%-10% necessary for normal protein function.

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9 Only three CBAVD patients were found with more than one CFFR mutation (AF508/L206W, AF508/R74W + D 1270N, R 117H/712-1G--~T), highlighting L206W, R74W/ T. Casals -M. Chill6n. Login to comment
59 Direct sequencing of these two abnormal fragments identified mutation R ll7H, a known Table 1 Semen analysis of patients with CAVD, given as the mean (range) CBAVD CUAVD (n = 27) (n = 10) Sperm (x 106/ml) 0 10.6 (0-90) Seminal volume (ml) 0.9 (0.2-3.1) 2.5 (0.4 5.4) pH 6.7 (6.0-8.0) 7.3 (6.4-7.7) Fructose (retool/l) 2.6 (0-9) 10.3 (3-) '~Citrate (mmol/l) 77.5 (11-188) 48.6 (36-88) ~Reference values: fructose, 8 28 retool/l; citrate, 10 35 retool/1 Table 2 CFTR mutation analysis in 30 CBAVD and 10 CUAVD patients (CBAVD congenital bilateral absence of the vas deferens, CUAVD congenital unilateral absence of the vas deferens, ND not determined, - absence of mutations, RRI recurrent respiratory infection, R rhinitis, RS rhino-sinusitis, BR.ASTH bronchitis asthmatic) Table 3 Congenital malformations associated with CAVD in 40 patients 207 Patient Age Phenotype Sweat test Mutation Other clinical (years) (mEq/l) features 1 37 CBAVD 108 1677delTA 2 28 CBAVD 50 G542X 3 28 CBAVD 118 - 4 33 CBAVD 90 AF508/L206W RRI, R 5 26 CBAVD 118 R117H/712-1G-+T 6 42 CBAVD 66 - RS 7 31 CBAVD 170 AF508 R 8 27 CBAVD 100 AF508/R74W + D1270N RRI, R 9 32 CBAVD 74 AE115 RS 10 35 CBAVD 90 - Nasal polyps 11 33 CBAVD 78 KI060T RI, family history 12 45 CBAVD 150 R334W RS 13 42 CBAVD 60 - 14 40 CBAVD 110 R 1070W RS 15 29 CBAVD 110 G542X 16 37 CBAVD 80 R117H RI, RS, BR.ASTH 17 37 CBAVD 85 - Asthma 18 46 CBAVD 15 R1162X 19 37 CBAVD 110 AF508 RS, diarrhoea 20 42 CBAVD 45 2789+5G--)A RI 21 49 CBAVD 95 AF508 22 36 CBAVD 70 AF508 RRI, RS 23 42 CBAVD 90 - 24 15 CBAVD 150 AF508 25 26 CBAVD 60 - 26 39 CBAVD 100 AF508 RRI, RS 27 33 CBAVD 57 AF508 RRI 28 33 CBAVD 80 G542X 29 34 CBAVD 78 - 30 32 CBAVD 113 G542X 31 33 CUAVD ND AF508 RS, pancreatitis 32 37 CUAVD ND - 33 31 CUAVD 77 - BR.ASTH 34 39 CUAVD ND - 35 40 CUAVD 40 - 36 33 CUAVD 59 - 37 40 CUAVD 90 - 38 47 CUAVD 40 - RRI 39 39 CUAVD 50 - 40 35 CUAVD 100 - No. Login to comment
89 Another abnormal DGGE fragment detected in exon 3 was the result of mutation R74W (Claustres et al. 1993); this mutation was found to be associated with mutation D1270N in exon 20 (Anguiano et al. 1992; C. F6rec and M. Claustres, personal communication). Login to comment
99 The third patient had AF508/R74W + D1270N, with clinical features of rhinitis and recurrent respiratory infections. Login to comment
100 We do not know which of the two mutations (R74W or D1270N, or both) is involved in the CBAVD phenotype. Login to comment

[hide] Is congenital bilateral absence of vas deferens a ... Am J Hum Genet. 1995 Jan;56(1):272-7. Mercier B, Verlingue C, Lissens W, Silber SJ, Novelli G, Bonduelle M, Audrezet MP, Ferec C
Is congenital bilateral absence of vas deferens a primary form of cystic fibrosis? Analyses of the CFTR gene in 67 patients.
Am J Hum Genet. 1995 Jan;56(1):272-7., [PMID:7529962]

Abstract [show]
Congenital bilateral absence of the vas deferens (CBAVD) is an important cause of sterility in men. Although the genetic basis of this condition is still unclear, it has been shown recently that some of these patients carry mutations in their cystic fibrosis transmembrane conductance regulator (CFTR) genes. To extend this observation, we have analyzed the entire coding sequence of the CFTR gene in a cohort of 67 men with CBAVD, who are otherwise healthy. We have identified four novel missense mutations (A800G, G149R, R258G, and E193K). We have shown that 42% of subjects were carriers of one CFTR allele and that 24% are compound heterozygous for CFTR alleles. Thus, we have been unable to identify 76% of these patients as carrying two CFTR mutations. Furthermore, we have described the segregation of CFTR haplotypes in the family of one CBAVD male; in this family are two male siblings, with identical CFTR loci but displaying different phenotypes, one of them being fertile and the other sterile. The data presented in this family, indicating a discordance between the CBAVD phenotype and a marked carrier (delta F508) chromosome, support the involvement of another gene(s), in the etiology of CBAVD.

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65 In addition, we identified the following missense mutations: four R668C, one A800G, one (G628R + S1235R, borne on the same chromosome), one (R74W + D1270N, borne on the same chromosome), six R117H, one F1052V, one R117C, one S1235R, one G149R, one R258G, two R347H, one R1066H, one R75L, and one E193K. Login to comment
77 of Patients Genotypea 1 AF508 + (G628R + S1235R) 1 AF508 + (R74W + D1270N) 2 AF508 + R668C 4 AF508 + R117H 1 AF508 + R258G 1 AF508 + R75L 1 E193K + N1303K 1 R347H + R1066H 1 R117C + W1282X 1 R553X + R668C 1 G149R + R668C 1 R117H+R117H 18 AF508/unidentified 4 W1282X/unidentified 1 G542X/unidentified 1 N1303K/unidentified 1 S1235R/unidentified 1 R347H/unidentified 1 A800G/unidentified 1 F1052V/unidentified 23 unidentified/unidentified a In parentheses are the two mutations located on the same haplotype. Login to comment
98 Two patients were carriers of two missense mutations on the same allele (G268R + S1235 R and R74W + D1270N) (table 1). Login to comment
99 The association of these two missense mutations on the same haplotype is interesting, as both S1235R and R74W have been independently reported elsewhere to be CFTR alleles (Claustres et al. 1993; Cuppens et al. 1993). Login to comment
100 We also had previously reported that haplotype R74W + D1270N was present in a healthy 23 le b 12 t 113 t 11,4 t *,13 13 a|13 1 131313 Figure I CFTR locus for brothers II-1 and II-4. Login to comment
117 These results show clearly that these two brothers are carrying two identical CFTR haplotypes and suggest that another locus could account for the phenotype observed for subject II,. Discussion mother of an affected child (Verlingue et al. 1993), her genotype being (R74W + D1270N) + 2183 AA--oG. If we consider that CBAVD may be a mild form of CF, these observations suggest that a second mutation in a CFTR allele may result in a reversion or partial reversion of phenotype. Login to comment

[hide] Sensitivity of single-strand conformation polymorp... Hum Mol Genet. 1994 May;3(5):801-7. Ravnik-Glavac M, Glavac D, Dean M
Sensitivity of single-strand conformation polymorphism and heteroduplex method for mutation detection in the cystic fibrosis gene.
Hum Mol Genet. 1994 May;3(5):801-7., [PMID:7521710]

Abstract [show]
The gene responsible for cystic fibrosis (CF) contains 27 coding exons and more than 300 independent mutations have been identified. An efficient and optimized strategy is required to identify additional mutations and/or to screen patient samples for the presence of known mutations. We have tested several different conditions for performing single-stranded conformation polymorphism (SSCP) analysis in order to determine the efficiency of the method and to identify the optimum conditions for mutation detection. Each exon and corresponding exon boundaries were amplified. A panel of 134 known CF mutations were used to test the efficiency of detection of mutations. The SSCP conditions were varied by altering the percentage and cross-linking of the acrylamide, employing MDE (an acrylamide substitute), and by adding sucrose and glycerol. The presence of heteroduplexes could be detected on most gels and in some cases contributed to the ability to distinguish certain mutations. Each analysis condition detected 75-98% of the mutations, and all of the mutations could be detected by at least one condition. Therefore, an optimized SSCP analysis can be used to efficiently screen for mutations in a large gene.

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120 Exon 1: S4X (24), 186-13C-G (F£rec et al., pers. comm.); Exon 2: G27X (Shacldeton and Harris, pers. comm.), Q30X (Chilldn aal., pers. comm.), R31L (Zielenski et al., pers. comm.), Q39X (25); Exon 3: 300delA (Malone et al., pers. comm.), W57G (Ferrari et al., pers. comm.), W57X (26), E60X (Malone et al., pers. comm.), R74W (Claustres et al., pers. comm.), R75Q (27), G85E (28), 394delTT (Claustres et al., pers. comm.), L88X (Maceketal., pers. comm.), L88S (Malone et al., pers. comm.), 405 + 1G-A (Dork and Tummler, pers. comm.); Exon 4: E92K (Chillon et al., pers. comm.), E92X (D6rk a al., pers. comm.), P99L (Schwartz and Holmberg, pers. comm.), 441delA (Zielenski et al., pers. comm.), 444delA (29), 457TAT-C- (F£rec et al., pers. comm., (21), Dl 10H (14), Rl 17C (D6rk et al., pers. comm.), Rl 17H (14), A120T (Chillon et al., pers. comm.), 541delC (30), 556delA (28), I148T (Rininsland et al., pers. comm.), Q151X (Shacldeton et al., pers. comm.), 621 + 1C-T (28), 622-2A-C (31); Exon5:G178R (28), 681delC (Zielenski a al., pers. comm.), 711 + 1G-T (28); Exon 6a: H199Y (Dork and Tummler, pers. comm.), H199Q (Dean etal., pers. comm.), L206W (Claustres et al., pers. comm.), Q220X (Shacldeton and Harris, pers. comm., Schwartz and Holmberg, pers. comm.), 852del22 (32); Exon 6b: 977insA (33); Exon7:F311L(34). Login to comment

[hide] Analysis of the 27 exons and flanking regions of t... Hum Mol Genet. 1993 Aug;2(8):1209-13. Claustres M, Laussel M, Desgeorges M, Giansily M, Culard JF, Razakatsara G, Demaille J
Analysis of the 27 exons and flanking regions of the cystic fibrosis gene: 40 different mutations account for 91.2% of the mutant alleles in southern France.
Hum Mol Genet. 1993 Aug;2(8):1209-13., [PMID:7691344]

Abstract [show]
In order to characterize the non-delta F508 mutations that account for 36% of cystic fibrosis (CF) chromosomes in Southern France in a sample of 137 patients, we have systematically screened the entire coding region and adjacent sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene by the single strand conformation polymorphism (SSCP) technique followed by direct sequencing of the mutant DNAs. We identified 13 novel mutations (9 reported in this paper) and 4 novel rare nucleotide sequence variations. Forty different mutations including delta F508, located in 15 exons, account for only 91.2% of mutants in a population originating from Southern France, in contrast with a recent report on the Celtic population of Brittany demonstrating that 90% of mutations can be detected with only three mutations. We present a very large spectrum of different CF mutations identified in a small geographical area.

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20 R74W. Login to comment
26 Mutations identified in a Southern french population mutation AF5O8 M1K 300delA P67L R74W G85E 394detTT 406-6 (T-C) Y122X I148T 621 + 1G-T 62/+2T-G L206W 1078deIT R334W R347H R347P AI507 1717-1G-A G542X R553X S549N G551D E585X 2184delA K710X R792X S945L Y1092X 3272-26A-G R1158X R1162X 3737delA 3659delC 11234V D1270N W1282X N13O3H N13O3K 4382delA Exon 10 1 3 3 3 3 3 intron 3 4 4 intron 4 intron 4 6a 7 7 7 7 10 intron 10 11 11 11 11 , 12 13 13 13 15 17b intron 17a 19 19 19 19 19 20 20 21 21 24 Amino acid change 3 bp deletion start-Lys at 1 frameshift Pro-Leu at67 Arg-Trp at 74 Gly-Glu at 85 frameshift splice mutation? Login to comment
53 SSCP aft Sequence Sequence I l-CT A C G T - -T 405+46 (G or T) R74W Figure 2. Login to comment
54 SSCP and sequence analysis of 309-bp PCR fragments containing exon 3 in a CF patient carrying both the possible mutation R74W and the rare variation 405 +46 (G or T). Login to comment
55 The black symbol indicates the presence of R74W, inherited from the mother, while a hatched half symbol indicates the presence of an unknown mutation inherited from the father. Login to comment
59 Previously undescribed polymorphisms Two rare variants have been identified in one CF patient each: 405+46 (G or T) in intron 3, which destroys a Nsil site and was found on the chromosome carrying the mutation R74W (Figure 2), and 3726 (G or T) in exon 19 that does not change PAGE Sequence G T 300delA 394delTT 394delTT Figure 3. Characterization of a 2-bp deletion in exon 3: 394delTT. Login to comment

[hide] Carbamazepine as a novel small molecule corrector ... J Biol Chem. 2013 Jul 19;288(29):20942-54. doi: 10.1074/jbc.M113.470948. Epub 2013 Jun 6. Chen PC, Olson EM, Zhou Q, Kryukova Y, Sampson HM, Thomas DY, Shyng SL
Carbamazepine as a novel small molecule corrector of trafficking-impaired ATP-sensitive potassium channels identified in congenital hyperinsulinism.
J Biol Chem. 2013 Jul 19;288(29):20942-54. doi: 10.1074/jbc.M113.470948. Epub 2013 Jun 6., [PMID:23744072]

Abstract [show]
ATP-sensitive potassium (KATP) channels consisting of sulfonylurea receptor 1 (SUR1) and the potassium channel Kir6.2 play a key role in insulin secretion by coupling metabolic signals to beta-cell membrane potential. Mutations in SUR1 and Kir6.2 that impair channel trafficking to the cell surface lead to loss of channel function and congenital hyperinsulinism. We report that carbamazepine, an anticonvulsant, corrects the trafficking defects of mutant KATP channels previously identified in congenital hyperinsulinism. Strikingly, of the 19 SUR1 mutations examined, only those located in the first transmembrane domain of SUR1 responded to the drug. We show that unlike that reported for several other protein misfolding diseases, carbamazepine did not correct KATP channel trafficking defects by activating autophagy; rather, it directly improved the biogenesis efficiency of mutant channels along the secretory pathway. In addition to its effect on channel trafficking, carbamazepine also inhibited KATP channel activity. Upon subsequent removal of carbamazepine, however, the function of rescued channels was recovered. Importantly, combination of the KATP channel opener diazoxide and carbamazepine led to enhanced mutant channel function without carbamazepine washout. The corrector effect of carbamazepine on mutant KATP channels was also demonstrated in rat and human beta-cells with an accompanying increase in channel activity. Our findings identify carbamazepine as a novel small molecule corrector that may be used to restore KATP channel expression and function in a subset of congenital hyperinsulinism patients.

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125 At 10 òe;M, the F27S and E128K mutations exhibited the greatest improvement to nearly the level seen with 5 òe;M glibenclamide; R74W, A116P, and V187D showed moderate responses; whereas G7R and N24K, which have less severe processing defects (31), had weak responses (Fig. 1C). Login to comment
127 At 10 òe;M, the F27S and E128K mutations exhibited the greatest improvement to nearly the level seen with 5 òe;M glibenclamide; R74W, A116P, and V187D showed moderate responses; whereas G7R and N24K, which have less severe processing defects (31), had weak responses (Fig. 1C). Login to comment

[hide] Effect of ivacaftor on CFTR forms with missense mu... J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23. Van Goor F, Yu H, Burton B, Hoffman BJ
Effect of ivacaftor on CFTR forms with missense mutations associated with defects in protein processing or function.
J Cyst Fibros. 2014 Jan;13(1):29-36. doi: 10.1016/j.jcf.2013.06.008. Epub 2013 Jul 23., [PMID:23891399]

Abstract [show]
BACKGROUND: Ivacaftor (KALYDECO, VX-770) is a CFTR potentiator that increased CFTR channel activity and improved lung function in patients age 6 years and older with CF who have the G551D-CFTR gating mutation. The aim of this in vitro study was to evaluate the effect of ivacaftor on mutant CFTR protein forms with defects in protein processing and/or channel function. METHODS: The effect of ivacaftor on CFTR function was tested in electrophysiological studies using a panel of Fischer rat thyroid (FRT) cells expressing 54 missense CFTR mutations that cause defects in the amount or function of CFTR at the cell surface. RESULTS: Ivacaftor potentiated multiple mutant CFTR protein forms that produce functional CFTR at the cell surface. These included mutant CFTR forms with mild defects in CFTR processing or mild defects in CFTR channel conductance. CONCLUSIONS: These in vitro data indicated that ivacaftor is a broad acting CFTR potentiator and could be used to help stratify patients with CF who have different CFTR genotypes for studies investigating the potential clinical benefit of ivacaftor.

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44 None M1V A46D E56K P67L R74W G85E E92K D110E D110H R117C R117H E193K L206W R334W I336K T338I S341P R347H R347P R352Q A455E L467P S492F F508del V520F A559T R560S R560T A561E Y569D D579G R668C L927P S945L S977F L997F F1052V H1054D K1060T L1065P R1066C R1066H R1066M A1067T R1070Q R1070W F1074L L1077P H1085R M1101K D1152H S1235R D1270N N1303K 0 100 200 300 400 500 600 * * * CFTR Mutation mRNA (% Normal CFTR) Fig. 1. Login to comment
64 Mutant CFTR form CFTR processing Mature/total % Normal CFTR Normal 0.89 &#b1; 0.01 100.0 &#b1; 18.5 G85E -0.05 &#b1; 0.04 -1.0 &#b1; 0.9 R560S 0.00 &#b1; 0.00 0.0 &#b1; 0.0 R1066C 0.02 &#b1; 0.01 0.0 &#b1; 0.0 S492F 0.00 &#b1; 0.00 0.1 &#b1; 0.1 R560T 0.01 &#b1; 0.01 0.2 &#b1; 0.1 V520F 0.05 &#b1; 0.03 0.3 &#b1; 0.2 M1101K 0.05 &#b1; 0.03 0.3 &#b1; 0.1 A561E 0.08 &#b1; 0.04 0.5 &#b1; 0.2 R1066M 0.02 &#b1; 0.02 0.5 &#b1; 0.4 N1303K 0.02 &#b1; 0.02 0.5 &#b1; 0.3 A559T 0.16 &#b1; 0.09 0.6 &#b1; 0.2 M1V 0.06 &#b1; 0.06 0.7 &#b1; 0.6 Y569D 0.11 &#b1; 0.04 0.6 &#b1; 0.2 R1066H 0.08 &#b1; 0.02a 0.7 &#b1; 0.2a L1065P 0.05 &#b1; 0.05 1.0 &#b1; 0.8 L467P 0.10 &#b1; 0.07 1.2 &#b1; 0.8 L1077P 0.08 &#b1; 0.04 1.5 &#b1; 0.6 A46D 0.21 &#b1; 0.08 1.9 &#b1; 0.5a E92K 0.06 &#b1; 0.05 1.9 &#b1; 1.3 H1054D 0.09 &#b1; 0.04 1.9 &#b1; 0.8 F508del 0.09 &#b1; 0.02a 2.3 &#b1; 0.5a H1085R 0.06 &#b1; 0.01a 3.0 &#b1; 0.7a I336K 0.42 &#b1; 0.05a 6.5 &#b1; 0.7a L206W 0.35 &#b1; 0.10a 6.8 &#b1; 1.7a F1074L 0.52 &#b1; 0.03a 10.9 &#b1; 0.6a A455E 0.26 &#b1; 0.10a 11.5 &#b1; 2.5a E56K 0.29 &#b1; 0.04a 12.2 &#b1; 1.5a R347P 0.48 &#b1; 0.04a 14.6 &#b1; 1.8a R1070W 0.61 &#b1; 0.04a 16.3 &#b1; 0.6a P67L 0.36 &#b1; 0.04a 28.4 &#b1; 6.8a R1070Q 0.90 &#b1; 0.01a 29.5 &#b1; 1.4a S977F 0.97 &#b1; 0.01a 37.3 &#b1; 2.4a A1067T 0.78 &#b1; 0.03a 38.6 &#b1; 6.1a D579G 0.72 &#b1; 0.02a 39.3 &#b1; 3.1a D1270N 1.00 &#b1; 0.00a,c 40.7 &#b1; 1.2a S945L 0.65 &#b1; 0.04a 42.4 &#b1; 8.9a L927P 0.89 &#b1; 0.01a,b 43.5 &#b1; 2.5a,b R117C 0.87 &#b1; 0.02a,b 49.1 &#b1; 2.9a,b T338I 0.93 &#b1; 0.03a,b 54.2 &#b1; 3.7a,b L997F 0.90 &#b1; 0.04a,b 59.8 &#b1; 10.4a,b D110H 0.97 &#b1; 0.01a,b 60.6 &#b1; 1.5a,b S341P 0.79 &#b1; 0.02a 65.0 &#b1; 4.9a,b R668C 0.94 &#b1; 0.03a,b 68.5 &#b1; 1.9a,b R74W 0.78 &#b1; 0.01a 69.0 &#b1; 2.7a,b D110E 0.92 &#b1; 0.05a,b 87.5 &#b1; 9.5a,b R334W 0.91 &#b1; 0.05a,b 97.6 &#b1; 10.0a,b K1060T 0.87 &#b1; 0.02a,b 109.9 &#b1; 28.0a,b R347H 0.96 &#b1; 0.02a,c 120.7 &#b1; 2.8a,b S1235R 0.96 &#b1; 0.00a,c 139.0 &#b1; 9.0a,b E193K 0.84 &#b1; 0.02a,b 143.0 &#b1; 17.1a,b R117H 0.86 &#b1; 0.01a,b 164.5 &#b1; 34.2a,b R352Q 0.98 &#b1; 0.01a,b 179.9 &#b1; 8.0a,c F1052V 0.90 &#b1; 0.01a,b 189.9 &#b1; 33.1a,b D1152H 0.96 &#b1; 0.02a,c 312.0 &#b1; 45.5a,b Notes to Table 1: Quantification of steady-state CFTR maturation expressed as the mean (&#b1;SEM; n = 5-9) ratio of mature CFTR to total CFTR (immature plus mature) or level of mature mutant CFTR relative to mature normal-CFTR (% normal CFTR) in FRT cells individually expressing CFTR mutations. Login to comment
74 Because the level of CFTR mRNA was similar across the panel of cell lines tested, the range in baseline activity and ivacaftor response likely reflects the severity of the functional defect and/or the 0 50 100 150 200 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L E56K P67L R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V Baseline With ivacaftor * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Chloride transport (% Normal) Mutant CFTR form 0 100 200 300 400 S341P R347P L467P S492F A559T A561E Y569D L1065P R1066C R1066M L1077P M1101K N1303K R560S L927P R560T H1085R V520F E92K M1V F508del H1054D I336K A46D G85E R334W T338I R1066H R352Q R117C L206W R347H S977F S945L A455E F1074L P67L E56K R1070W D110H D579G D110E R1070Q L997F A1067T E193K R117H R74W K1060T R668C D1270N D1152H S1235R F1052V * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Mature CFTR (% Normal) Mutant CFTR form A B Fig. 2. Login to comment
82 Mutation Patientsa Chloride transport (bc;A/cm2 ) Chloride transport (% normal) EC50 Baseline With ivacaftor Baseline With ivacaftor Fold increase over baselineb Normal 204.5 &#b1; 33.3 301.3 &#b1; 33.8c 100.0 &#b1; 16.3 147.3 &#b1; 16.5c 1.5 266 &#b1; 42 G551D 1282 1.5 &#b1; 0.7 113.2 &#b1; 13.0c 1.0 &#b1; 0.5 55.3 &#b1; 6.3c 55.3 312 &#b1; 73 F1052V 12 177.3 &#b1; 13.7 410.2 &#b1; 11.3c 86.7 &#b1; 6.7 200.7 &#b1; 5.6c 2.3 177 &#b1; 14 S1235R ND 160.6 &#b1; 25.7 352.1 &#b1; 43.4c 78.5 &#b1; 12.6 172.2 &#b1; 21.2c 2.2 282 &#b1; 104 D1152H 185 117.3 &#b1; 23.0 282.7 &#b1; 46.9c 57.4 &#b1; 11.2 138.2 &#b1; 22.9c 2.4 178 &#b1; 67 D1270N 32 109.5 &#b1; 20.5 209.5 &#b1; 27.4c 53.6 &#b1; 10.0 102.4 &#b1; 13.4c 1.9 254 &#b1; 56 R668C 45 99.0 &#b1; 9.4 217.6 &#b1; 11.7c 48.4 &#b1; 4.6 106.4 &#b1; 5.7c 2.2 517 &#b1; 105 K1060T ND 89.0 &#b1; 9.8 236.4 &#b1; 20.3c 43.5 &#b1; 4.8 115.6 &#b1; 9.9c 2.7 131 &#b1; 73 R74W 25 86.8 &#b1; 26.9 199.1 &#b1; 16.8c 42.5 &#b1; 13.2 97.3 &#b1; 8.2c 2.3 162 &#b1; 17 R117H 739 67.2 &#b1; 13.3 274.1 &#b1; 32.2c 32.9 &#b1; 6.5 134.0 &#b1; 15.7c 4.1 151 &#b1; 14 E193K ND 62.2 &#b1; 9.8 379.1 &#b1; 1.1c 30.4 &#b1; 4.8 185.4 &#b1; 1.0c 6.1 240 &#b1; 20 A1067T ND 55.9 &#b1; 3.2 164.0 &#b1; 9.7c 27.3 &#b1; 1.6 80.2 &#b1; 4.7c 2.9 317 &#b1; 214 L997F 27 43.7 &#b1; 3.2 145.5 &#b1; 4.0c 21.4 &#b1; 1.6 71.2 &#b1; 2.0c 3.3 162 &#b1; 12 R1070Q 15 42.0 &#b1; 0.8 67.3 &#b1; 2.9c 20.6 &#b1; 0.4 32.9 &#b1; 1.4c 1.6 164 &#b1; 20 D110E ND 23.3 &#b1; 4.7 96.4 &#b1; 15.6c 11.4 &#b1; 2.3 47.1 &#b1; 7.6c 4.1 213 &#b1; 51 D579G 21 21.5 &#b1; 4.1 192.0 &#b1; 18.5c 10.5 &#b1; 2.0 93.9 &#b1; 9.0c 8.9 239 &#b1; 48 D110H 30 18.5 &#b1; 2.2 116.7 &#b1; 11.3c 9.1 &#b1; 1.1 57.1 &#b1; 5.5c 6.2 249 &#b1; 59 R1070W 13 16.6 &#b1; 2.6 102.1 &#b1; 3.1c 8.1 &#b1; 1.3 49.9 &#b1; 1.5c 6.2 158 &#b1; 48 P67L 53 16.0 &#b1; 6.7 88.7 &#b1; 15.7c 7.8 &#b1; 3.3 43.4 &#b1; 7.7c 5.6 195 &#b1; 40 E56K ND 15.8 &#b1; 3.1 63.6 &#b1; 4.4c 7.7 &#b1; 1.5 31.1 &#b1; 2.2c 4.0 123 &#b1; 33 F1074L ND 14.0 &#b1; 3.4 43.5 &#b1; 5.4c 6.9 &#b1; 1.6 21.3 &#b1; 2.6c 3.1 141 &#b1; 19 A455E 120 12.9 &#b1; 2.6 36.4 &#b1; 2.5c 6.3 &#b1; 1.2 17.8 &#b1; 1.2c 2.8 170 &#b1; 44 S945L 63 12.3 &#b1; 3.9 154.9 &#b1; 47.6c 6.0 &#b1; 1.9 75.8 &#b1; 23.3c 12.6 181 &#b1; 36 S977F 9 11.3 &#b1; 6.2 42.5 &#b1; 19.1c 5.5 &#b1; 3.0 20.8 &#b1; 9.3c 3.8 283 &#b1; 36 R347H 65 10.9 &#b1; 3.3 106.3 &#b1; 7.6c 5.3 &#b1; 1.6 52.0 &#b1; 3.7c 9.8 280 &#b1; 35 L206W 81 10.3 &#b1; 1.7 36.4 &#b1; 2.8c 5.0 &#b1; 0.8 17.8 &#b1; 1.4c 3.6 101 &#b1; 13 R117C 61 5.8 &#b1; 1.5 33.7 &#b1; 7.8c 2.9 &#b1; 0.7 16.5 &#b1; 3.8c 5.7 380 &#b1; 136 R352Q 46 5.5 &#b1; 1.0 84.5 &#b1; 7.8c 2.7 &#b1; 0.5 41.3 &#b1; 3.8c 15.2 287 &#b1; 75 R1066H 29 3.0 &#b1; 0.3 8.0 &#b1; 0.8c 1.5 &#b1; 0.1 3.9 &#b1; 0.4c 2.6 390 &#b1; 179 T338I 54 2.9 &#b1; 0.8 16.1 &#b1; 2.4c 1.4 &#b1; 0.4 7.9 &#b1; 1.2c 5.6 334 &#b1; 38 R334W 150 2.6 &#b1; 0.5 10.0 &#b1; 1.4c 1.3 &#b1; 0.2 4.9 &#b1; 0.7c 3.8 259 &#b1; 103 G85E 262 1.6 &#b1; 1.0 1.5 &#b1; 1.2 0.8 &#b1; 0.5 0.7 &#b1; 0.6 NS NS A46D ND 2.0 &#b1; 0.6 1.1 &#b1; 1.1 1.0 &#b1; 0.3 0.5 &#b1; 0.6 NS NS I336K 29 1.8 &#b1; 0.2 7.4 &#b1; 0.1c 0.9 &#b1; 0.1 3.6 &#b1; 0.1c 4 735 &#b1; 204 H1054D ND 1.7 &#b1; 0.3 8.7 &#b1; 0.3c 0.8 &#b1; 0.1 4.2 &#b1; 0.1c 5.3 187 &#b1; 20 F508del 29,018 0.8 &#b1; 0.6 12.1 &#b1; 1.7c 0.4 &#b1; 0.3 5.9 &#b1; 0.8c 14.8 129 &#b1; 38 M1V 9 0.7 &#b1; 1.4 6.5 &#b1; 1.9c 0.4 &#b1; 0.7 3.2 &#b1; 0.9c 8.0 183 &#b1; 85 E92K 14 0.6 &#b1; 0.2 4.3 &#b1; 0.8c 0.3 &#b1; 0.1 2.1 &#b1; 0.4c 7.0 198 &#b1; 46 V520F 58 0.4 &#b1; 0.2 0.5 &#b1; 0.2 0.2 &#b1; 0.1 0.2 &#b1; 0.1 NS NS H1085R ND 0.3 &#b1; 0.2 2.1 &#b1; 0.4 0.2 &#b1; 0.1 1.0 &#b1; 0.2 NS NS R560T 180 0.3 &#b1; 0.3 0.5 &#b1; 0.5 0.1 &#b1; 0.1 0.2 &#b1; 0.2 NS NS L927P 15 0.2 &#b1; 0.1 10.7 &#b1; 1.7c 0.1 &#b1; 0.1 5.2 &#b1; 0.8c 52.0 313 &#b1; 66 R560S ND 0.0 &#b1; 0.1 -0.2 &#b1; 0.2 0.0 &#b1; 0.0 -0.1 &#b1; 0.1 NS NS N1303K 1161 0.0 &#b1; 0.0 1.7 &#b1; 0.3 0.0 &#b1; 0.0 0.8 &#b1; 0.2 NS NS M1101K 79 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1077P 42 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066M ND 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R1066C 100 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS L1065P 25 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS Y569D 9 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS A561E ND 0.0 &#b1; 0.1 0.0 &#b1; 0.1 0.0 &#b1; 0.0 0.0 &#b1; 0.1 NS NS A559T 43 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S492F 16 0.0 &#b1; 0.0 1.7 &#b1; 1.2 0.0 &#b1; 0.0 0.8 &#b1; 0.6 NS NS L467P 16 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS R347P 214 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 0.0 &#b1; 0.0 NS NS S341P 9 0.0 &#b1; 0.0 0.2 &#b1; 0.2 0.0 &#b1; 0.0 0.1 &#b1; 0.1 NS NS a Number of individuals with the individual mutation in the CFTR-2 database (www.CFTR2.org). Login to comment
92 Mutant CFTR forms that did not significantly respond to ivacaftor under the experimental conditions used in this study were generally associated with severe defects in CFTR processing A B C D E F 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 S1235R D1152H F1052V D1270N ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R668C K1060T R74W R117H ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 E193K A1067T L997F R1070Q ivacaftor [Log M] Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) Chloride Transport ( &#b5;A/cm 2 ) 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 D110E D579G D110H R1070W ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F1074L E56K P67L A455E ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 R347H S945L L206W S977F ivacaftor [Log M] 0 100 200 300 400 -8 -6 -4 0 T338I R1066H R117C R352Q ivacaftor [Log M] 0 100 200 300 400 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K ivacaftor [Log M] 0 5 10 15 20 -9 -8 -7 -6 -5 -4 0 F508del R334W H1054D E92K R1066H T338I ivacaftor [Log M] G H I Fig. 3. Login to comment
116 Other examples of complex CFTR alleles include the number of TG repeats in intron 8 along with the 5T CFTR mutation (e.g., TG11-5T, TG12-5T, TG13-5T), R668C-G576A-D443Y, and R74W-D1270N [8,16]. Login to comment

[hide] Defining the disease liability of variants in the ... Nat Genet. 2013 Oct;45(10):1160-7. doi: 10.1038/ng.2745. Epub 2013 Aug 25. Sosnay PR, Siklosi KR, Van Goor F, Kaniecki K, Yu H, Sharma N, Ramalho AS, Amaral MD, Dorfman R, Zielenski J, Masica DL, Karchin R, Millen L, Thomas PJ, Patrinos GP, Corey M, Lewis MH, Rommens JM, Castellani C, Penland CM, Cutting GR
Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene.
Nat Genet. 2013 Oct;45(10):1160-7. doi: 10.1038/ng.2745. Epub 2013 Aug 25., [PMID:23974870]

Abstract [show]
Allelic heterogeneity in disease-causing genes presents a substantial challenge to the translation of genomic variation into clinical practice. Few of the almost 2,000 variants in the cystic fibrosis transmembrane conductance regulator gene CFTR have empirical evidence that they cause cystic fibrosis. To address this gap, we collected both genotype and phenotype data for 39,696 individuals with cystic fibrosis in registries and clinics in North America and Europe. In these individuals, 159 CFTR variants had an allele frequency of l0.01%. These variants were evaluated for both clinical severity and functional consequence, with 127 (80%) meeting both clinical and functional criteria consistent with disease. Assessment of disease penetrance in 2,188 fathers of individuals with cystic fibrosis enabled assignment of 12 of the remaining 32 variants as neutral, whereas the other 20 variants remained of indeterminate effect. This study illustrates that sourcing data directly from well-phenotyped subjects can address the gap in our ability to interpret clinically relevant genomic variation.

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147 Included among the variants meeting neither clinical nor functional criteria are those that have previously been associated with variable penetrance (such as p.Asp1152His), variants that have been reported as part of complex alleles in which the disease liability of each variant individually could not be determined (such as the pair p.Arg74Trp and p.Asp1270Asn) and variants with incomplete clinical or functional analysis. Login to comment

[hide] Genetics of cystic fibrosis: CFTR mutation classif... Int J Biochem Cell Biol. 2014 Jul;52:94-102. doi: 10.1016/j.biocel.2014.02.023. Epub 2014 Mar 12. Fanen P, Wohlhuter-Haddad A, Hinzpeter A
Genetics of cystic fibrosis: CFTR mutation classifications toward genotype-based CF therapies.
Int J Biochem Cell Biol. 2014 Jul;52:94-102. doi: 10.1016/j.biocel.2014.02.023. Epub 2014 Mar 12., [PMID:24631642]

Abstract [show]
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes an epithelial anion channel. Since the identification of the disease in 1938 and up until 2012, CF patients have been treated exclusively with medications aimed at bettering their respiratory, digestive, inflammatory and infectious symptoms. The identification of the CFTR gene in 1989 gave hopes of rapidly finding a cure for the disease, for which over 1950 mutations have been identified. Since 2012, recent approaches have enabled the identification of small molecules targeting either the CFTR protein directly or its key processing steps, giving rise to novel promising therapeutic tools. This review presents the current CFTR mutation classifications according to their clinical consequences and to their effect on the structure and function of the CFTR channel. How these classifications are essential in the establishment of mutation-targeted therapeutic strategies is then discussed. The future of CFTR-targeted treatment lies in combinatory therapies that will enable CF patients to receive a customized treatment.

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70 Group A Group B Group C Group D Classic-CF CF-causing mutations Non-classic CF CFTR-related disorder associated mutations No clinical consequence Unknown clinical relevance All mutations in Table 2 and 711 + 3A > G*, R117H-T5*, D1152H*, L206W*, TG13-T5* TG13-T5a , R117H-T5a , D1152Ha , L206Wa , L997F, M952I, D565Ga , TG11-T5b , R117H-T7b , D443Y-G576A-R668C, R74W-D1270N, R75Qb TG11-T5b , R117H-T7b , R75Qb , 875 + 40A/G, M470V, T854T, P1290P, I807M, I521F, R74W, F508C, I506V, I148T All mutations (mostly missense) not yet analyzed or undergoing functional analysis a Mutations that may belong either to Group A or to Group B. b Mutations that may belong either to Group B or to Group C. Login to comment

[hide] Mechanisms of CFTR functional variants that impair... PLoS Genet. 2014 Jul 17;10(7):e1004376. doi: 10.1371/journal.pgen.1004376. eCollection 2014 Jul. LaRusch J, Jung J, General IJ, Lewis MD, Park HW, Brand RE, Gelrud A, Anderson MA, Banks PA, Conwell D, Lawrence C, Romagnuolo J, Baillie J, Alkaade S, Cote G, Gardner TB, Amann ST, Slivka A, Sandhu B, Aloe A, Kienholz ML, Yadav D, Barmada MM, Bahar I, Lee MG, Whitcomb DC
Mechanisms of CFTR functional variants that impair regulated bicarbonate permeation and increase risk for pancreatitis but not for cystic fibrosis.
PLoS Genet. 2014 Jul 17;10(7):e1004376. doi: 10.1371/journal.pgen.1004376. eCollection 2014 Jul., [PMID:25033378]

Abstract [show]
CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system.

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116 CFTR variant %Cases %Uctrls OR p-value %Cases w/N34S OR w/N34S p-value w/N34S F508C 0.5 0.3 1.58 0.21 0.0 0.00 0.67 R1162L 0.5 0.5 1.13 0.29 1.8 4.03 0.17 I1027T 0.5 0.3 1.99 0.17 0.0 0.00 0.70 R31C 0.3 0.7 0.42 0.088 0.0 0.00 0.52 I148T 0.3 0.4 0.75 0.27 0.0 0.00 0.63 R297Q 0.3 0.2 1.89 0.21 0.0 0.00 0.76 R74W 0.2 0.2 0.85 0.29 0.0 0.00 0.71 F1052V 0.1 0.2 0.63 0.27 0.0 0.00 0.76 I807M 0.1 0.1 1.26 0.30 0.0 0.00 0.83 R258G 0.1 0.1 1.26 0.30 0.0 0.00 0.83 G1069R 0.1 0.0 0.13 0.0 V201M 0.0 0.1 0.17 0.0 0.00 0.83 Of the 81 CFTR mutations tested in the cohort, 43 were observed at least once in cases or controls. Login to comment
269 67 SNPs (125GtoC, 1716G.A, 1717-1G.A, 1898+1G.A, 2183AA.G, 2184delA, 2789+5G.A, 3120+1G.A, 3659delC, 3849+10kbC.T, 621+ 1G.T, 711+5G.A, A455E, D110H, D1152H, D1270N, D443Y, D579G, F1052V, F1074L, F508C, F508del, G1069R, G1244E, G1349D, G178R, G542X, G551D, G551S, I1131L/V, I148T, I336K/T, I507del, I807M, IVS8T5, K1180T, L1065P, L967S, L997F, M1V, M470V, M952I, M952T, N1303K, P67L, Q1463Q, R1070Q, R1162X, R117C, R117H, R170H, R258G, R297Q, R31C, R352Q, R553X, R668C, R74W, R75Q, S1235R, S1255P, S485R, S977F, T338I, T854T, V201M, W1282X) were multiplexed into 6 wells; 14 SNPs (S492F, S945L, R74Q, R560T, R1162L, G85E, I1027T, R334W, R347P, G576A, 711+1G.T, 1001+11C.T, P1290P, 3199del6) were ascertained separately via TaqMan Gene Expression Assays, with repeat confirmation of all positive results. Login to comment

[hide] Full-open and closed CFTR channels, with lateral t... Cell Mol Life Sci. 2015 Apr;72(7):1377-403. doi: 10.1007/s00018-014-1749-2. Epub 2014 Oct 7. Mornon JP, Hoffmann B, Jonic S, Lehn P, Callebaut I
Full-open and closed CFTR channels, with lateral tunnels from the cytoplasm and an alternative position of the F508 region, as revealed by molecular dynamics.
Cell Mol Life Sci. 2015 Apr;72(7):1377-403. doi: 10.1007/s00018-014-1749-2. Epub 2014 Oct 7., [PMID:25287046]

Abstract [show]
In absence of experimental 3D structures, several homology models, based on ABC exporter 3D structures, have provided significant insights into the molecular mechanisms underlying the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride channel whose defects are associated with cystic fibrosis (CF). Until now, these models, however, did not furnished much insights into the continuous way that ions could follow from the cytosol to the extracellular milieu in the open form of the channel. Here, we have built a refined model of CFTR, based on the outward-facing Sav1866 experimental 3D structure and integrating the evolutionary and structural information available today. Molecular dynamics simulations revealed significant conformational changes, resulting in a full-open channel, accessible from the cytosol through lateral tunnels displayed in the long intracellular loops (ICLs). At the same time, the region of nucleotide-binding domain 1 in contact with one of the ICLs and carrying amino acid F508, the deletion of which is the most common CF-causing mutation, was found to adopt an alternative but stable position. Then, in a second step, this first stable full-open conformation evolved toward another stable state, in which only a limited displacement of the upper part of the transmembrane helices leads to a closure of the channel, in a conformation very close to that adopted by the Atm1 ABC exporter, in an inward-facing conformation. These models, supported by experimental data, provide significant new insights into the CFTR structure-function relationships and into the possible impact of CF-causing mutations.

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350 R74W (which is reported to be of varying clinical consequence) is located in the vicinity of a large aromatic cluster, including F77, F78, W79, F81, F83, and Y84; the substitution of this arginine by a tryptophan might thus destabilize the local geometry. Login to comment

[hide] Analysis of cystic fibrosis gene mutations in chil... J Med Case Rep. 2014 Oct 10;8:339. doi: 10.1186/1752-1947-8-339. Dell'Edera D, Benedetto M, Gadaleta G, Carone D, Salvatore D, Angione A, Gallo M, Milo M, Pisaturo ML, Di Pierro G, Mazzone E, Epifania AA
Analysis of cystic fibrosis gene mutations in children with cystic fibrosis and in 964 infertile couples within the region of Basilicata, Italy: a research study.
J Med Case Rep. 2014 Oct 10;8:339. doi: 10.1186/1752-1947-8-339., [PMID:25304080]

Abstract [show]
INTRODUCTION: Cystic fibrosis is the most common autosomal recessive genetic disease in the Caucasian population. Extending knowledge about the molecular pathology on the one hand allows better delineation of the mutations in the CFTR gene and the other to dramatically increase the predictive power of molecular testing. METHODS: This study reports the results of a molecular screening of cystic fibrosis using DNA samples of patients enrolled from January 2009 to December 2013. Patients were referred to our laboratory for cystic fibrosis screening for infertile couples. In addition, we identified the gene mutations present in 76 patients affected by cystic fibrosis in the pediatric population of Basilicata. RESULTS: In the 964 infertile couples examined, 132 subjects (69 women and 63 men) resulted heterozygous for one of the CFTR mutations, with a recurrence of carriers of 6.85%. The recurrence of carriers in infertile couples is significantly higher from the hypothetical value of the general population (4%). CONCLUSIONS: This study shows that in the Basilicata region of Italy the CFTR phenotype is caused by a small number of mutations. Our aim is to develop a kit able to detect not less than 96% of CTFR gene mutations so that the relative risk for screened couples is superimposable with respect to the general population.

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59 As mentioned before, molecular screening Table 2 Comparison between the results obtained in this study and those obtained in a previous study Castaldo et al. [14] Mutations observed in the present study F508del 55.8% (29) 48.62% (141) N1303K 3.8% (2) 9.31% (27) G542X 3.8% (2) 8.96% (26) W1282X 3.8% (2) 1.03% (3) 2183AA>G 5.8% (3) 2.76% (8) R1162X 0 0 1717-1G>A 1.9% (1) 0 T338I 0 0 R347P 0 0.69% (2) 711+5G>A 0 0 852del22 5.8% (3) 1.03% (3) 4382delA 0 0.69% (2) 1259insA 0 0.34% (1) 4016insT 0 0.34% (1) R553X 0 0.34% (1) R1158X 0 0 L1077P 0 1.03% (3) I502T 0 0 3849+10kbC>T 1.9% (1) 0.34% (1) D579G 0 0.69% (2) G1244E 3.8% (2) 0 G1349D 0 0.34% (1) 2789+5G>A 0 1.03% (3) 711+1G>T 0 0 L1065P 0 0 2522insC 0 0 E585X 0 0 G85E 0 0 G178R 0 0 D1152H 0 3.10% (9) I148T-3195del6 0 0 I148T (alone) 0 4.48% (13) R334W 0 0 DI507 0 0.69% (2) I1005R 0 0 3272-26A>G 0 0 2711delT 0 0 L558S 1.9% (1) 0.34% (1) W1063X 0 0 D110H 0 0 S549R (A>C) 1.9% (1) 0.69% (2) 2184insA 0 0 3131del22 0 0 Table 2 Comparison between the results obtained in this study and those obtained in a previous study (Continued) R709N 0 0 A349V 0 0 4015insA 0 0 Y849X 1.9% (1) 0.34% (1) G551D 0 1.03% (3) 621+3A>G 0 0.34% (1) E831X 0 0 I507del 0 0.69% (2) IVS8 TG12/t5 0 1.03% (3) H139R (A->G) 0 0.34% (1) 1248+1G>A 0 0.34% (1) R74W;V201M;D1270N 0 0.69% (2) S1455X 0 0.34% (1) dele 2,3 (21kb) 0 0.34% (1) 991del5 0 0.34% (1) UNKNOWN 7 %(4) 4.83% (14) F508C 0 0.69% (2) TOTAL 52 290 of CF is highly recommended in the USA by the National Institutes of Health Consensus Development Conference Statement on genetic testing for cystic fibrosis [17]. Login to comment

[hide] Clinical expression of patients with the D1152H CF... J Cyst Fibros. 2015 Jul;14(4):447-52. doi: 10.1016/j.jcf.2014.12.012. Epub 2015 Jan 10. Terlizzi V, Carnovale V, Castaldo G, Castellani C, Cirilli N, Colombo C, Corti F, Cresta F, D'Adda A, Lucarelli M, Lucidi V, Macchiaroli A, Madarena E, Padoan R, Quattrucci S, Salvatore D, Zarrilli F, Raia V
Clinical expression of patients with the D1152H CFTR mutation.
J Cyst Fibros. 2015 Jul;14(4):447-52. doi: 10.1016/j.jcf.2014.12.012. Epub 2015 Jan 10., [PMID:25583415]

Abstract [show]
BACKGROUND: Discordant results were reported on the clinical expression of subjects bearing the D1152H CFTR mutation, and also for the small number of cases reported so far. METHODS: A retrospective review of clinical, genetic and biochemical data was performed from individuals homozygous or compound heterozygous for the D1152H mutation followed in 12 Italian cystic fibrosis (CF) centers. RESULTS: 89 subjects carrying at least D1152H on one allele were identified. 7 homozygous patients had very mild clinical expression. Over half of the 74 subjects compound heterozygous for D1152H and a I-II-III class mutation had borderline or pathological sweat test and respiratory or gastrointestinal symptoms; one third had pulmonary bacteria colonization and 10/74 cases had complications (i.e. diabetes, allergic bronchopulmonary aspergillosis, and hemoptysis). However, their clinical expression was less severe as compared to a group of CF patients homozygous for the F508del mutation. Finally, 8 subjects compound heterozygous for D1152H and a IV-V class mutation showed very mild disease. CONCLUSIONS: The natural history of subjects bearing the D1152H mutation is widely heterogeneous and is influenced by the mutation in trans.

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85 Legacy name Protein name CDNA name Patients Homozygous for the D1152Ha D1152H p.Asp1152His c.3454GNC 7 Compound heterozygous for class I-II-III mutationsa : 74 F508del p.Phe508del c.1521_1523delCTT 43 G542X p.Gly542X c.1624GNT 7 N1303K p.Asn1303Lys c.3909CNG 4 1717-1GNA No protein name c.1585-1GNA 4 R1158X p.Arg1158X c.3472CNT 4 2183AANG p.Lys684SerfsX38 c.2051_2052delAAinsG 2 W1282X p.Trp1282X c.3846GNA 2 711 + 1GNT No protein name c.579 + 1GNT 1 Y849X p.Tyr849X c.2547CNA 1 L1065P p.Leu1065Pro c.3194 TNC 1 4016insT p.Ser1297PhefsX5 c.3884_3885insT 1 R1066H p.Arg1066His c.3197GNA 2 R1066C p.Arg1066Cys c.3196CNT 1 4382delA p.Glu1418ArgfsX14 c.4251delA 1 Compound heterozygous for class IV-V mutationsa : 8 (TG)12T5 No protein name Not available 2 2789 + 5GNA No protein name c.2657 + 5GNA 1 D579G p.Asp579Gly c.1736ANG 1 [R74W;V201M; D1270N] No protein name Not available 1 3849 + 10KbCNT No protein name c.3717 + 12191CNT 1 R347H p.Arg347His c.1040GNA 1 R347P p.Arg347Pro c.1040GNC 1 a Protein name and cDNA name from the CFTR2 database (http://www.http. com//www.cftr2) and http://www.genet.sickkids.on.ca/Home.html. Login to comment

[hide] Improving newborn screening for cystic fibrosis us... Genet Med. 2015 Feb 12. doi: 10.1038/gim.2014.209. Baker MW, Atkins AE, Cordovado SK, Hendrix M, Earley MC, Farrell PM
Improving newborn screening for cystic fibrosis using next-generation sequencing technology: a technical feasibility study.
Genet Med. 2015 Feb 12. doi: 10.1038/gim.2014.209., [PMID:25674778]

Abstract [show]
Purpose:Many regions have implemented newborn screening (NBS) for cystic fibrosis (CF) using a limited panel of cystic fibrosis transmembrane regulator (CFTR) mutations after immunoreactive trypsinogen (IRT) analysis. We sought to assess the feasibility of further improving the screening using next-generation sequencing (NGS) technology.Methods:An NGS assay was used to detect 162 CFTR mutations/variants characterized by the CFTR2 project. We used 67 dried blood spots (DBSs) containing 48 distinct CFTR mutations to validate the assay. NGS assay was retrospectively performed on 165 CF screen-positive samples with one CFTR mutation.Results:The NGS assay was successfully performed using DNA isolated from DBSs, and it correctly detected all CFTR mutations in the validation. Among 165 screen-positive infants with one CFTR mutation, no additional disease-causing mutation was identified in 151 samples consistent with normal sweat tests. Five infants had a CF-causing mutation that was not included in this panel, and nine with two CF-causing mutations were identified.Conclusion:The NGS assay was 100% concordant with traditional methods. Retrospective analysis results indicate an IRT/NGS screening algorithm would enable high sensitivity, better specificity and positive predictive value (PPV). This study lays the foundation for prospective studies and for introducing NGS in NBS laboratories.Genet Med advance online publication 12 February 2015Genetics in Medicine (2015); doi:10.1038/gim.2014.209.

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31 Both methods used 5 &#b5;l of isolated DNA for the NGS assay. NGS assay for detection of CFTR mutations/variants CFTR mutations are described using both the international nomenclature of the Human Genome Variation Society Mutations that have varying consequences c.3454G>C (D1152H) c.3154T>G (F1052V) c.3208C>T (R1070W) c.2930C>T (S977F) - c.3808G>A (D1270N) c.3205G>A (G1069R) c.350G>A (R117H) PolyTG/ polyT - c.1736A>G (D579G) c.3209G>A (R1070Q) c.220C>T (R74W) - - Mutations still under evaluation c.2657ߙ+ߙ2_2657ߙ+ߙ3insA (2789ߙ+ߙ2insA) c.680T>G (L227R) c.1705T>G (Y569D) - - c.1841A>G (D614G) c.1673T>C (L558S) - - - c.3700A>G (I1234V) c. Login to comment

[hide] A Genotypic-Oriented View of CFTR Genetics Highlig... Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229. Lucarelli M, Bruno SM, Pierandrei S, Ferraguti G, Stamato A, Narzi F, Amato A, Cimino G, Bertasi S, Quattrucci S, Strom R
A Genotypic-Oriented View of CFTR Genetics Highlights Specific Mutational Patterns Underlying Clinical Macrocategories of Cystic Fibrosis.
Mol Med. 2015 Apr 21;21:257-75. doi: 10.2119/molmed.2014.00229., [PMID:25910067]

Abstract [show]
Cystic fibrosis (CF) is a monogenic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The genotype-phenotype relationship in this disease is still unclear, and diagnostic, prognostic and therapeutic challenges persist. We enrolled 610 patients with different forms of CF and studied them from a clinical, biochemical, microbiological and genetic point of view. Overall, there were 125 different mutated alleles (11 with novel mutations and 10 with complex mutations) and 225 genotypes. A strong correlation between mutational patterns at the genotypic level and phenotypic macrocategories emerged. This specificity appears to largely depend on rare and individual mutations, as well as on the varying prevalence of common alleles in different clinical macrocategories. However, 19 genotypes appeared to underlie different clinical forms of the disease. The dissection of the pathway from the CFTR mutated genotype to the clinical phenotype allowed to identify at least two components of the variability usually found in the genotype-phenotype relationship. One component seems to depend on the genetic variation of CFTR, the other component on the cumulative effect of variations in other genes and cellular pathways independent from CFTR. The experimental dissection of the overall biological CFTR pathway appears to be a powerful approach for a better comprehension of the genotype-phenotype relationship. However, a change from an allele-oriented to a genotypic-oriented view of CFTR genetics is mandatory, as well as a better assessment of sources of variability within the CFTR pathway.

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278 The [R74W;V201M;D1270N] (p. Login to comment
279 [Arg74Trp; Val201Met;Asp1270Asn]) complex allele was found in 2 patients (1 CF-PS and 1 CBAVD). Login to comment
363 [72G>C;164+2T>G] uncertain: CF-PI and/or CF-PS L24F nd; 296+2T>G nd R31C c.91C>T CFTR-RD non CF-causing p.Arg31Cys S42F c.125C>T uncertain: found only with an unknown allele in trans nd p.Ser42Phe E56G c.167G>A CBAVD nd p.Glu56Lys [R74W;V201M;D1270N] c. Login to comment
364 [220C>T;601G>A;3808G>A] uncertain: CF-PS and/or CFTR-RD and/or CBAVD R74W varying clinical consequence; V201M nd; p. Login to comment
365 [Arg74Trp;Val201Met;Asp1270Asn] D1270N varying clinical consequence [359insT;(TG)12T5] c. Login to comment

[hide] The improvement of the best practice guidelines fo... Eur J Hum Genet. 2015 May 27. doi: 10.1038/ejhg.2015.99. Girardet A, Viart V, Plaza S, Daina G, De Rycke M, Des Georges M, Fiorentino F, Harton G, Ishmukhametova A, Navarro J, Raynal C, Renwick P, Saguet F, Schwarz M, SenGupta S, Tzetis M, Roux AF, Claustres M
The improvement of the best practice guidelines for preimplantation genetic diagnosis of cystic fibrosis: toward an international consensus.
Eur J Hum Genet. 2015 May 27. doi: 10.1038/ejhg.2015.99., [PMID:26014425]

Abstract [show]
Cystic fibrosis (CF) is one of the most common indications for preimplantation genetic diagnosis (PGD) for single gene disorders, giving couples the opportunity to conceive unaffected children without having to consider termination of pregnancy. However, there are no available standardized protocols, so that each center has to develop its own diagnostic strategies and procedures. Furthermore, reproductive decisions are complicated by the diversity of disease-causing variants in the CFTR (cystic fibrosis transmembrane conductance regulator) gene and the complexity of correlations between genotypes and associated phenotypes, so that attitudes and practices toward the risks for future offspring can vary greatly between countries. On behalf of the EuroGentest Network, eighteen experts in PGD and/or molecular diagnosis of CF from seven countries attended a workshop held in Montpellier, France, on 14 December 2011. Building on the best practice guidelines for amplification-based PGD established by ESHRE (European Society of Human Reproduction and Embryology), the goal of this meeting was to formulate specific guidelines for CF-PGD in order to contribute to a better harmonization of practices across Europe. Different topics were covered including variant nomenclature, inclusion criteria, genetic counseling, PGD strategy and reporting of results. The recommendations are summarized here, and updated information on the clinical significance of CFTR variants and associated phenotypes is presented.European Journal of Human Genetics advance online publication, 27 May 2015; doi:10.1038/ejhg.2015.99.

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87 [Gln359Lys; Thr360Lys] L558S c.1673 T4C p.Leu558Ser Y569D c.1705 T4G p.Tyr569Asp D579G c.1736 A4G p.Asp579Gly D614G c.1841 A4G p.Asp614Gly S977F c.2930C4T p.Ser977Phe F1052V c.3154 T4G p.Phe1052Val G1069R c.3205G4A p.Gly1069Arg R1070Q c.3209G4A p.Arg1070Gln D1152H c.3454G4C p.Asp1152His I1234V c.3700 A4G p.Ile1234Val 5T c.1210 - 12[5] Examples of common not CF-causing variantsc R31C c.91C4T p.Arg31Cys R74W c.220C4T p.Arg74Trp R75Q c.224G4A p.Arg75Gln I148T c.443 T4C p.Ile148Thr M470V c.1408 A4G p.Met470Val G576A c.1727G4C p.Gly576Ala R668C c.2002C4T p.Arg668Cys V754M c.2260G4A p.Val754Met L997F c.2991G4C p.Leu997Phe I1027T c.3080 T4C p.Ile1027Thr R1070W c.3208C4T p.Arg1070Trp R1162L c.3485G4T p.Arg1162Leu Table 1 (Continued) HGVS nomenclature Legacy name cDNA nucleotide name Protein name S1235R c.3705 T4G p.Ser1235Arg D1270N c.3808G4A p.Asp1270Asn 7T c.1210-12[7] Abbreviation: HGVS, Human Genome Variation Society. Login to comment
99 Missense variants R74W, R1070W, D1270N are classified as 'indeterminate` by Sosnay et al.,17 however, as they are frequently found in trans with a severe CF variant in asymptomatic individuals (including fertile fathers), they may not be sufficient to cause disease.19 Moreover, they are often associated within the same allele (eg in cis), forming various combinations ('complex alleles`) depending on individuals, so that their disease liability is questionable. Login to comment
100 Examples: [R74W;D1270N] c. Login to comment
101 [220C4T;3808G4A] [R74W;V201M;D1270N] c. Login to comment
102 [220C4T;601G4A;3808G4A] [R74W;R1070W;D1270N] c. Login to comment
211 Nat Genet 2013; 45: 1160-1167. 18 Thauvin-Robinet C, Munck A, Huet F et al: The very low penetrance of cystic fibrosis for the R117H mutation: a reappraisal for genetic counselling and newborn screening. J Med Genet 2009; 46: 752-758. 19 Claustres M, Altieri JP, Guittard C, Templin C, Chevalier-Ports F, Des Georges M: Are p.148 T, p.R74W and p.D1270N CF causing mutations? Login to comment

[hide] Newborn Screening for Cystic Fibrosis in Californi... Pediatrics. 2015 Dec;136(6):1062-72. doi: 10.1542/peds.2015-0811. Epub 2015 Nov 16. Kharrazi M, Yang J, Bishop T, Lessing S, Young S, Graham S, Pearl M, Chow H, Ho T, Currier R, Gaffney L, Feuchtbaum L
Newborn Screening for Cystic Fibrosis in California.
Pediatrics. 2015 Dec;136(6):1062-72. doi: 10.1542/peds.2015-0811. Epub 2015 Nov 16., [PMID:26574590]

Abstract [show]
OBJECTIVES: This article describes the methods used and the program performance results for the first 5 years of newborn screening for cystic fibrosis (CF) in California. METHODS: From July 16, 2007, to June 30, 2012, a total of 2 573 293 newborns were screened for CF by using a 3-step model: (1) measuring immunoreactive trypsinogen in all dried blood spot specimens; (2) testing 28 to 40 selected cystic fibrosis transmembrane conductance regulator (CFTR) mutations in specimens with immunoreactive trypsinogen values >/=62 ng/mL (top 1.6%); and (3) performing DNA sequencing on specimens found to have only 1 mutation in step 2. Infants with >/=2 mutations/variants were referred to CF care centers for diagnostic evaluation and follow-up. Infants with 1 mutation were considered carriers and their parents offered telephone genetic counseling. RESULTS: Overall, 345 CF cases, 533 CFTR-related metabolic syndrome cases, and 1617 carriers were detected; 28 cases of CF were missed. Of the 345 CF cases, 20 (5.8%) infants were initially assessed as having CFTR-related metabolic syndrome, and their CF diagnosis occurred after age 6 months (median follow-up: 4.5 years). Program sensitivity was 92%, and the positive predictive value was 34%. CF prevalence was 1 in 6899 births. A total of 303 CFTR mutations were identified, including 78 novel variants. The median age at referral to a CF care center was 34 days (18 and 37 days for step 2 and 3 screening test-positive infants, respectively). CONCLUSIONS: The 3-step model had high detection and low false-positive levels in this diverse population.

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No. Sentence Comment
125 No mutations on panel 9 c.2822delT/ c.2822delT (n = 3) Hispanic (n = 7) Meconium ileus (n = 4) c.1153_1154insAT (1288insTA)/ c.1153_1154insAT (1288insTA)b Other/multiple (n = 2) Family history (n = 4) c.165-3C.T (297-3C.T)/ c.4147_4148insA (4279insA)/ c.4201G.T (E14013) Symptoms (n = 8) c.220C.T (R74W)/ c.601G.A (V201M)/ c.2562T.G (T854T or 2694T/G)/ c. Login to comment